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                                                                     EXHIBIT 4.3

                           REVOLVING CREDIT AGREEMENT

     REVOLVING CREDIT AGREEMENT dated as of December 21, 2005, by and among
VERASUN ENERGY CORPORATION, a South Dakota corporation (the "Borrower"), FIRST
NATIONAL BANK OF OMAHA, a national banking association with principal offices in
Omaha, Nebraska (the "Bank"), VERASUN AURORA CORPORATION, a South Dakota
corporation ("Aurora"), VERASUN FORT DODGE, LLC, a Delaware limited liability
company ("Fort Dodge"), and VERASUN CHARLES CITY, LLC, a Delaware limited
liability company ("Charles City"). The parties hereto hereby agree as follows:

                                    ARTICLE I

                        DEFINITIONS AND ACCOUNTING TERMS

     SECTION 1.01. DEFINED TERMS. As used in this Agreement, the following terms
have the following meanings (terms defined in the singular to have the same
meaning when used in the plural and vice versa):

     "Account(s)" means, as to the Borrower and each Restricted Subsidiary, at
any relevant time, one or more Account(s), as defined in the UCC, and any other
rights to receive payments for services rendered or Goods provided.

     "Additional Conditions Precedent" shall have the meaning given such term in
Section 3.02 of this Agreement.

     "Additional Subsidiary" means, as to the Borrower, (1) a corporation, other
than Aurora, of which shares of stock having ordinary voting power (other than
stock having such power only by reason of the happening of a contingency) to
elect a majority of the board of directors or other managers of such corporation
are at the time owned, or the management of which is otherwise controlled,
directly or indirectly through one or more intermediaries, or both, by the
Borrower; or (2) a limited liability company, other than a Current Subsidiary,
of which the Borrower owns a greater than 50% membership interest, has the
ability to elect the majority of the managers of the limited liability company,
or the management of which is otherwise controlled, directly or indirectly
through one or more intermediaries, or both, by the Borrower; or (3) any
partnership or other entity of which the Borrower owns a greater than 50%
interest or the management of which is controlled, directly or indirectly
through one or more intermediaries, or both, by the Borrower.

     "Adjustment Date" means, the first day of February, May, August and
November of each year during the period in which any amounts are due and owing
to the Bank pursuant to the transactions provided for in this Agreement.

     "Affiliate" means any Person, other than a Subsidiary, (1) which directly
or indirectly controls, or is controlled by, or is under common control with the
Borrower or a Subsidiary; (2) which directly or indirectly beneficially owns or
holds ten percent (10%) or more of any interest of the Borrower or any
Subsidiary; (3) ten percent (10%) or more of the voting stock of which is
directly or indirectly beneficially owned or held by the Borrower or a
Subsidiary; or (4) ten percent (10%) or more of any membership interest or other
interest in any other entity of which is


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directly or indirectly beneficially owned or held by the Borrower or a
Subsidiary. The term "control" means the possession, directly or indirectly, of
the power to direct or cause the direction of the management and policies of a
Person, whether through the ownership of voting securities, through the
ownership of interests in a limited liability company, partnership or other
entity, by contract, or otherwise.

     "Agreement" means this Revolving Credit Agreement and all schedules and
exhibits to this Agreement, in each case as amended, supplemented, or modified
from time to time.

     "Aurora" shall have the meaning given such term in the preamble hereto.

     "Authorized Person" means, an individual authorized to act on behalf of the
Borrower or a Restricted Subsidiary, in accordance with its Organizational
Documents or appropriate resolutions adopted in accordance therewith.

     "Bank" shall have the meaning given such term in the preamble hereto.

     "Bankruptcy Code" means Title 11 of the United States Code, as now
constituted or hereafter amended.

     "Borrower" shall have the meaning given such term in the preamble hereto.

     "Borrowing Base" means the lesser of:

          (a) Thirty Million and No/100ths Dollars ($30,000,000.00); or

          (b) The aggregate of (i) seventy-five percent (75%) of the Borrower's
          and each Restricted Subsidiary's Eligible Accounts, plus (ii)
          seventy-five percent (75%) of Borrower's and each Restricted
          Subsidiary's Inventory, at current value on the date reported,
          determined in accordance with GAAP, less (iii) the face amount of all
          Letters of Credit issued by the Bank pursuant to the Letter of Credit
          Facility and all outstanding letters of credit issued by the Bank on
          behalf of a Restricted Subsidiary to be replaced pursuant to Section
          5.13, as to the date of such determination.

     "Borrowing Base Certificate" means the fully completed and executed
certificate, in the form of Exhibit "A" attached to this Agreement and
incorporated herein by this reference, certified by the chief financial officer
of the Borrower to be true and correct and delivered to, and accepted by, the
Bank, which acceptance shall not be unreasonably withheld, at the time (a) of
each borrowing under the terms and provisions of this Agreement setting forth
the Borrowing Base and reflecting that the amount of the then requested
borrowing, when added to the existing borrowings of the Borrower hereunder and
the existing Letters of Credit, does not exceed the Borrowing Base, and (b) as
provided in Section 5.09 (5) of this Agreement.


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     "Business Day" means any day other than a Saturday, Sunday, or other day on
which the Bank is authorized or required to close under the laws of the State of
Nebraska or the United States.

     "Charles City" shall have the meaning given such term in the preamble
hereto.

     "Closing Date" means the date on which this Agreement is executed and
delivered by the Borrower, each Restricted Subsidiary, and the Bank.

     "Closing Fee" means the amount of Seventy Five Thousand Dollars
($75,000.00) to be paid by the Borrower to the Bank on the Closing Date.

     "Code" means the Internal Revenue Code of 1986, as amended from time to
time, and the regulations and published interpretations thereof.

     "Collateral" means all property which is subject or is to be subject to the
Lien granted by the Security Agreement, the Subsidiary Security Agreements or
the Control Agreements.

     "Commitment" means the Bank's obligation to make Loans to the Borrower
pursuant to Section 2.01 in the amount referred to therein upon compliance with
the terms and provisions of this Agreement.

     "Commitment Letter" means the letter from the Bank to the Borrower dated
November 28, 2005, attached hereto as Exhibit "B" and incorporated herein by
this reference.

     "Conditions Precedent" means the Initial Conditions Precedent and
Additional Conditions Precedent.

     "Control Agreements" mean the following, collectively: (1) control
agreement of the Borrower in the form attached hereto as Exhibit "C" and
incorporated herein by this reference and for the benefit of the Bank granting
the Bank a perfected security interest in the Collateral described in the
Security Agreement, (2) control agreement of Aurora in the form attached hereto
as Exhibit "D" and incorporated herein by this reference and for the benefit of
the Bank granting the Bank a perfected security interest in the Collateral
described in the respective Subsidiary Security Agreement, (3) control agreement
of Charles City in the form attached hereto as Exhibit "E" and incorporated
herein by this reference and for the benefit of the Bank granting the Bank a
perfected security interest in the Collateral described in the respective
Subsidiary Security Agreement, (4) control agreement of Fort Dodge in the form
attached hereto as Exhibit "F" and incorporated herein by this reference and for
the benefit of the Bank granting the Bank a perfected security interest in the
Collateral described in the respective Subsidiary Security Agreement, and (5)
the additional control agreements delivered to the Bank by additional Restricted
Subsidiaries.

     "Current Subsidiary" means each of the Subsidiaries listed on Exhibit "S".


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     "Default" means any of the events specified in Section 7.01, whether or not
any requirement for the giving of notice, the lapse of time, or both, or any
other condition, has been satisfied.

     "Eligible Account" means an Account of the Borrower or a Restricted
Subsidiary, that conforms and continues to conform to the following conditions:

          A. The Account arose from a bona fide outright sale of Goods, as
     defined in the UCC, by the Borrower or any Restricted Subsidiary, or from
     services performed by the Borrower or any Restricted Subsidiary and such
     Goods have been shipped to the appropriate account debtors or their
     designees (or the sale has otherwise been consummated), or the services
     have been performed for the appropriate Account debtors, or services
     performed or invoices delivered in accordance with the terms and provisions
     of a contract pursuant to which the Borrower or a Restricted Subsidiary, as
     the case may be, is performing services or providing Goods which is due and
     payable not more than thirty (30) days from the date of the invoice
     therefor;

          B. Neither the Borrower nor any Restricted Subsidiary has received any
     notice of the filing of a petition in bankruptcy or insolvency laws by or
     against, the Account debtor. Upon the receipt by the Borrower or a
     Restricted Subsidiary of any such notice, it will immediately give the Bank
     written advice thereof;

          C. The Account debtor is not a Subsidiary or other Affiliate of the
     Borrower; and

          D. After ten (10) days prior written notice to the Borrower, the Bank
     shall have the right to deem an account ineligible because of reasonable
     uncertainty about the credit worthiness of the account debtor or because
     the Bank otherwise reasonably considers the collateral value thereof to the
     Bank to be impaired or its ability to realize such value to be insecure. In
     the event of any dispute, under the foregoing criteria, about whether an
     Account is or has ceased to be an Account, following ten (10) days written
     notice to the Borrower, the decision of the Bank shall control.

     "Eurodollar Business Day" means a Business Day on which commercial banks
are open for international business (including dealings in United States dollar
deposits) in London, England.

     "Event of Default" means any of the events specified in Section 7.01,
provided that any requirement for the giving of notice, the lapse of time, or
both, or any other condition, has been satisfied.

     "Fort Dodge" shall have the meaning given such term in the preamble hereto.

     "GAAP" means generally accepted accounting principles in the United States.

     "Goods" shall have the meaning given that term in the UCC.


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     "Initial Conditions Precedent" shall have the meaning given such term in
Section 3.01 of this Agreement.

     "Interest Period" means, initially, the period commencing on the date of
the Operating Note and ending on December 31, 2005 and the last day of each
calendar quarter thereafter, provided that:

          (a) subject to clauses (b) and (c) below, for any calendar month, any
          Interest Period which would otherwise end on a day which is not a
          Eurodollar Business Day shall be extended to the next succeeding
          Eurodollar Business Day unless such next succeeding Eurodollar
          Business Day falls in the next succeeding calendar month, in which
          case such Interest Period shall end on the last Eurodollar Business
          Day occurring during the current calendar month;

          (b) subject to clause (c) below, any Interest Period which begins on
          the last Eurodollar Business Day of a calendar month (or a day for
          which there is no numerically corresponding Eurodollar Business Day in
          the calendar month at the end of such Interest Period) shall end on
          the last Eurodollar Business Day of the last calendar month occurring
          during such Interest Period; and

          (c) notwithstanding anything contained herein to the contrary, no
          Interest Period shall extend beyond the Maturity Date for the
          Operating Note.

     "Inventory" means at any time the Borrower's and each Restricted
Subsidiary's Inventory, as defined in the UCC, that is and continues to be (i)
in good and merchantable condition, (ii) held for sale or to be furnished under
contracts for Goods or services to which the Borrower or any Restricted
Subsidiary is a party, (iii) owned by the Borrower or a Restricted Subsidiary,
free and clear of any Lien, other than the Lien of the Bank as provided for
herein, and (iv) not subject to any conditional sale, consignment or other
vendor's rights of ownership or revendication.

     "Letter of Credit" means one or more letters of credit issued under and
pursuant to the Letter of Credit Facility by execution and delivery by the
Borrower of the Bank's standard form promissory note and continuing letter of
credit agreement relating to each such letter of credit, pursuant to the Bank's
customary policies and in accordance with the terms and provisions of the Bank's
standardized documents, to be executed and delivered to the Bank at the time of
issuance of each such Letter of Credit.

     "Letter of Credit Facility" means the commitment of the Bank to issue
Letters of Credit in the maximum amount of Ten Million and No/100ths Dollars
($10,000,000.00) and taken into consideration in determining the Borrowing Base.

     "Letter of Credit Fee" means the fee payable by the Borrower to the Bank,
within ten (10) days of the end of each calendar quarter following the Closing
Date that a Letter of Credit has been provided by the Bank pursuant to the
Letter of Credit Facility, equal to Two Hundred


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Twenty Five (225) basis points (2.25%) times the amount outstanding, calculated
on a daily basis, of the Letters of Credit during such calendar quarter.

     "LIBOR" shall mean, for any day or period, the "London Interbank Offered
Rate" for such day or period as quoted by the Bloomberg service or such other
vendor as may be chosen by the Bank in its sole discretion.

     "LIBOR Base Rate" shall mean, with respect to the applicable Interest
Period, (a) the LIBOR Index Rate for such Interest Period, if such rate is
available, or (b) if the LIBOR Index Rate cannot be determined, the average
(rounded upward, if necessary, to the next higher one one-hundredth (1/100) of
one percent (1%)) of the respective rates per annum of interest at which
deposits in dollars are offered to the Bank in the London interbank market by
two (2) Eurodollar dealers of recognized standing, selected by the Bank in its
sole discretion, at such time on the date two (2) Eurodollar Business Days
before the first day of such Interest Period as the Bank in its sole discretion
elects, for delivery on the first day of the applicable Interest Period for a
number of days comparable to the number of days in such Interest Period and in
an amount approximately equal to the principal amount of the Obligations then
outstanding.

     "LIBOR Index Rate" shall mean, with respect to the applicable Interest
Period, the rate per annum (rounded upwards, if necessary, to the next higher
one one-hundredth (1/100) of one percent (1%)) for deposits in U.S. Dollars for
a period equal to such Interest Period, which appears on the Bank's information
vendor as of 9:00 a.m. (Omaha, Nebraska time) on the day two (2) Eurodollar
Business Days before the first day of such Interest Period. The term "the Bank's
information vendor" means the Bloomberg service or such other internationally
recognized service for the purpose of displaying the British Bankers'
Association Interest Settlement Rates for U.S. Dollar Deposits as chosen by the
Bank in its sole discretion.

     "LIBOR Rate" shall mean, with respect to any Interest Period, the quotient
(rounded upwards, if necessary, to the next higher one one-hundredth (1/100) of
one percent (1%)) of the (i) LIBOR Base Rate divided by (ii) one (1.00) minus
the applicable LIBOR Reserve Percentage. The LIBOR Rate shall be adjusted
automatically on and as of the effective date of any change in the LIBOR Reserve
Percentage.

     "LIBOR Reserve Percentage" shall mean for any day that percentage
(expressed as a decimal) which is in effect on such day, as prescribed by the
Board of Governors of the Federal Reserve System (or any successor), for
determining the maximum reserve requirement for a member bank of the Federal
Reserve System with respect to "Eurocurrency Liabilities" (or in respect of any
other category of liabilities which includes deposits by reference to which the
interest rate on LIBOR loans is determined or any category of extensions of
credit or other assets which include loans by a non-United States office of any
bank to United States residents). The LIBOR Rate shall be adjusted automatically
on and as of the effective date of any change in the LIBOR Reserve Percentage.

     "Lien" means any mortgage, deed of trust, pledge, security interest,
hypothecation, assignment, deposit arrangement, encumbrance, lien (statutory or
other), or preference, priority,


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or other security agreement or preferential arrangement, charge, or encumbrance
of any kind or nature whatsoever (including, without limitation, any conditional
sale or other title retention agreement, any financing lease having
substantially the same economic effect as any of the foregoing, and the filing
of any financing statement under the Uniform Commercial Code or comparable law
of any jurisdiction to evidence any of the foregoing).

     "Loan" or "Loans" shall have the meaning assigned to such term in Section
2.01.

     "Loan Documents" means, collectively, this Agreement, the Operating Note,
the Security Agreement, the Control Agreement, Subsidiary Guaranties, the
Subsidiary Security Agreements, each agreement entered into by the Borrower
relating to the Letters of Credit, and any other instrument or document executed
and delivered in connection with this Agreement.

     "Maturity Date" means December 31, 2008.

     "Minimum Tangible Net Worth" means, measured on a calendar quarterly basis
beginning on December 31, 2005 and continuing thereafter as of the last day of
each calendar quarter through the Maturity Date, combined Tangible Net Worth of
the Borrower of One Hundred Five Million Dollars ($105,000,000.00).

     "Minimum Working Capital" means, measured on a calendar quarterly basis
beginning on December 31, 2005 and continuing thereafter as of the last day of
each calendar quarter through the Maturity Date, combined Working Capital of the
Borrower and the Restricted Subsidiaries of Fifteen Million Dollars
($15,000,000.00).

     "Obligation" or "Obligations" shall mean, collectively, (1) each of the
obligations and covenants of Borrower and each of the Restricted Subsidiaries
under this Agreement, any of the Loan Documents and all modifications,
substitutions, extensions and renewals of each, whether absolute or contingent,
liquidated or unliquidated, existing now or arising in the future and (2) all
present and future indebtedness and obligations of Borrower to the Bank whether
direct, indirect, absolute, or contingent and whether arising by note, guaranty,
overdraft, or otherwise.

     "Operating Note" means the operating note of the Borrower, in the form
attached hereto as Exhibit "G" and incorporated herein by this reference.

     "Organizational Documents" means the articles of incorporation and bylaws
of a corporation, the certificate or articles of formation and operating
agreement of a limited liability company, or partnership agreement of a
partnership, as applicable.

     "Person" means an individual, partnership, limited liability company,
corporation, business trust, joint stock company, trust, unincorporated
association, joint venture, governmental authority, or other entity of whatever
nature.

     "Principal Office" means the Bank's office at 1620 Dodge Street, STOP 1050,
Omaha, Nebraska 68197.


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     "Restricted Funds" means cash of the Borrower which is held in escrow or in
trust for the benefit of a third party, including but not limited to the funds
held in escrow from the sale of Senior Secured Notes relating to the
construction of the ethanol facility for Charles City.

     "Restricted Subsidiary" means, collectively, Aurora, Charles City and Fort
Dodge and any other Subsidiary formed or acquired by Borrower or a Subsidiary in
accordance with the terms and provisions hereof, which owns or operates a
ethanol production facility and which executes and delivers to the Bank a
Subsidiary Guaranty and Control Agreement pursuant to the terms and provisions
of this Agreement.

     "Security Agreement" means the Security Agreement, in the form attached
hereto as Exhibit "H" and incorporated herein by this reference, to be delivered
by the Borrower under the terms of this Agreement to secure the Obligations.

     "Senior Secured Notes" means the senior secured notes of the Borrower due
December 15, 2012.

     "Senior Note Documents" means the indenture relating to the Senior Secured
Notes and the purchase agreement pursuant to which the Senior Secured Notes are,
or are to be, sold by the Borrower to the initial purchasers thereof.

     "Subsidiary" means, as to the Borrower, each Current Subsidiary and any
Additional Subsidiary formed or acquired in accordance herewith, whether a
Restricted Subsidiary or an Unrestricted Subsidiary.

     "Subsidiary Guaranties" means the following, collectively: (1) the
unlimited and irrevocable guaranty of Aurora in the form attached hereto as
Exhibit "I" and incorporated herein by this reference and secured by the
Subsidiary Security Agreement of Aurora and the Control Agreement of Aurora, (2)
the unlimited and irrevocable guaranty of Charles City in the form attached
hereto as Exhibit "J" and incorporated herein by this reference and secured by
the Subsidiary Security Agreement of Charles City and the Control Agreement of
Charles City, (3) the unlimited guaranty of Fort Dodge in the form attached
hereto as Exhibit "K" and incorporated herein by this reference and secured by
the Subsidiary Security Agreement of Fort Dodge and the Control Agreement of
Fort Dodge, and (4) the additional guaranties delivered to the Bank by
additional Restricted Subsidiaries.

     "Subsidiary Guarantors" means Aurora, Charles City, Fort Dodge, and each of
the additional Restricted Subsidiaries.

     "Subsidiary Security Agreements" means the following, collectively: (1) the
security agreement by and between the Bank and Aurora in the form attached
hereto as Exhibit "L" and incorporated herein by this reference, (2) the
security agreement by and between the Bank and Charles City in the form attached
hereto as Exhibit "M" and incorporated herein by this reference, (3) the
security agreement by and between the Bank and Fort Dodge in the form


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attached hereto as Exhibit "N" and incorporated herein by this reference, and
(4) the security agreement by and between the Bank and each additional
Restricted Subsidiary.

     "Tangible Net Worth" means the consolidated total assets less the
consolidated total liabilities of the Borrower less, without duplication, the
following types of assets: (a) leasehold improvements; (b) receivables or other
amounts (i) due from any shareholder, member, employee or other Affiliate or
Subsidiary of the Borrower or (ii) which, in accordance with GAAP, are
considered to be doubtful or uncollectible in the ordinary course of business;
(c) investments, other than cash, cash equivalents or readily marketable
securities; (d) goodwill, patents, copyrights, mailing lists, trade names,
trademarks, servicing rights, organizational and franchise costs, bond
underwriting costs and other like assets properly classified as intangible; and
(e) treasury stock or treasury membership units or interests in the Borrower..

     "UCC" means the Uniform Commercial Code of the State of Nebraska, as
amended from time to time.

     "Unrestricted Subsidiary" means each Current Subsidiary (other than
Restricted Subsidiaries) and each other Subsidiary formed or acquired by
Borrower or a Subsidiary in accordance with the terms and provisions hereof
which is not a Restricted Subsidiary and is designated at the time of formation
or acquisition as an "Unrestricted Subsidiary".

     "Unused Commitment Fee" means the fee payable by the Borrower to the Bank
within ten (10) days of the end of each calendar quarter following the Closing
Date, commencing on December 31, 2005, equal to twenty five (25) basis points
(0.25%) times the amount of the unused portion of the Commitment, on a daily
basis, during such calendar quarter. The amount of the Unused Commitment Fee
shall vary, depending on the Working Capital of the Borrower and the Restricted
Subsidiaries as of the end of each calendar quarter such that, (a) if the
Working Capital of the Borrower and the Restricted Subsidiaries is equal to or
greater than Fifteen Million Dollars ($15,000,000.00) but less than Thirty
Million Dollars ($30,000,000.00) as of the end of such calendar quarter, the
Unused Commitment Fee shall be twenty five (25) basis points (0.25%) times the
amount of the unused portion of the Commitment, on a daily basis, during such
calendar quarter, (b) if the Working Capital of the Borrower and the Restricted
Subsidiaries is equal to or greater than Thirty Million Dollars ($30,000,000.00)
but less than Forty Million Dollars ($40,000,000.00) as of the end of such
calendar quarter, the Unused Commitment Fee shall be twenty (20) basis points
(0.20%) times the amount of the unused portion of the Commitment, on a daily
basis, during such calendar quarter, and (c) if the Working Capital of the
Borrower and the Restricted Subsidiaries is equal to or greater than Forty
Million Dollars ($40,000,000.00), the Unused Commitment Fee shall be fifteen
(15) basis points (0.15%) times the amount of the unused portion of the
Commitment, on a daily basis, during such calendar quarter.

     "Working Capital" means the consolidated current assets of the Borrower and
the Restricted Subsidiaries, less (i) to the extent classified as a current
asset, investments in, or loans to, a Subsidiary, employee or other Affiliate of
the Borrower or any Restricted Subsidiary, (ii) current liabilities of the
Borrower or any Restricted Subsidiary, and (iii) any Restricted Funds.


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     SECTION 1.02. ACCOUNTING TERMS. All accounting terms not specifically
defined herein shall be construed in accordance with GAAP consistent with those
applied in the preparation of the financial statements of the Borrower pursuant
to the terms and provisions hereof, and all financial data submitted pursuant to
this Agreement shall be prepared in accordance with such principles.

                                   ARTICLE II

                          AMOUNT AND TERMS OF THE LOANS

     SECTION 2.01. REVOLVING CREDIT. The Bank agrees on the terms and conditions
hereinafter set forth, to make loans (the "Loans") to the Borrower from time to
time during the period from the Closing Date of this Agreement up to, but not
including, the Maturity Date in an aggregate principal amount not to exceed at
any time outstanding Thirty Million and No/100ths Dollars ($30,000,000.00) upon
delivery by the Borrower to the Bank of a Borrowing Base Certificate relating
thereto reasonably acceptable to the Bank pursuant to the terms and provisions
of this Agreement (the "Commitment"). Each Loan which shall not utilize the
Commitment in full shall be in an amount not less than One Hundred Thousand and
No/100ths Dollars ($100,000.00). Within the limits of the Commitment, the
Borrower may borrow, prepay and reborrow under this Section 2.01. The Bank's
obligation to make Loans hereunder shall be subject to the following
limitations: (i) the Bank will make Loans in an aggregate principal amount not
to exceed the Borrowing Base, and (ii) the Bank will make Loans provided the
Conditions Precedent are satisfied. It is the intention of the parties that the
outstanding balance of the Operating Note shall not exceed the Borrowing Base,
and if at any time said balance exceeds the Borrowing Base, the Borrower shall
forthwith pay the Bank sufficient funds to reduce the balance of the Operating
Note until it is in compliance with this requirement. Provided that no Letters
of Credit are outstanding, the Borrower may elect to terminate the Operating
Note and the Letter of Credit Facility at any time, without penalty, upon
written notice to the Bank. In the event the Borrower so elects to terminate the
Operating Note and the Letter of Credit Facility, the aggregate principal amount
of the Operating Note outstanding, together with any accrued and unpaid interest
thereon, shall be due and payable to the Bank on the date of such election, if
not sooner paid and the Operating Note and the Letter of Credit Facility shall
be deemed for all purposes terminated and the Bank shall have no further or
additional obligation to loan funds to the Borrower or issue Letters of Credit
pursuant to the terms and provisions of this Agreement.

     SECTION 2.02. NOTICE AND MANNER OF BORROWING. Upon receipt by the Bank of a
request for a Loan not later than 2:00 P.M. (Central Time) on the date Borrower
is requesting such Loan, provided Borrower has upon fulfilled or complied with
the applicable Conditions Precedent, the Bank will make such Loan available to
the Borrower in immediately available funds by crediting the amount thereof to
the Borrower's account with the Bank.

     SECTION 2.03. INTEREST. The Borrower shall pay interest to the Bank on the
outstanding and unpaid principal amount of the Operating Note in accordance with
the terms and provisions thereof.


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     SECTION 2.04. UNUSED COMMITMENT FEE. The Borrower shall pay the Unused
Commitment Fee in arrears on a calendar quarter basis.

     SECTION 2.05. LETTER OF CREDIT FEE. The Borrower shall pay the Letter of
Credit Fee in arrears on a calendar quarter basis.

     SECTION 2.06. CLOSING FEE. The Borrower shall pay the Closing Fee to the
Bank, in immediately available funds, on the Closing Date.

     SECTION 2.07. NOTE. All Loans made by the Bank under this Agreement shall
be evidenced by, and repaid with interest in accordance with, the Operating
Note. The Bank is hereby authorized by the Borrower to endorse on the schedule
attached to the Operating Note or otherwise on the books and records of the Bank
the amount of each Loan and of each payment of principal received by the Bank on
account of the Loans, which endorsement shall, in the absence of manifest error
or mutual agreement among the parties, be conclusive as to the outstanding
balance of the Loans made by the Bank; provided, however, that the failure to
make such notation with respect to any Loan or payment shall not limit or
otherwise affect the obligations of the Borrower under this Agreement or the
Operating Note.

     SECTION 2.08. METHOD OF PAYMENT. The Borrower shall make each payment under
this Agreement and under the Operating Note not later than 2:00 P.M. (Central
Time) on the date when due in lawful money of the United States to the Bank at
its Principal Office in immediately available funds. The Borrower hereby
authorizes the Bank, if and to the extent Bank receives telephonic request from
an officer or Authorized Person to take such action, to charge from time to time
against any account of the Borrower with the Bank any amount requested. Whenever
any payment to be made under this Agreement or under the Operating Note shall be
stated to be due on a day other than a Business Day, such payment shall be made
on the next succeeding Business Day, and such extension of time shall in such
case be included in the computation of the payment of interest.

     SECTION 2.09. USE OF PROCEEDS. The proceeds of the Loans hereunder shall be
used by the Borrower to finance the operational needs of Borrower and the
Subsidiaries (including without limitation, funding of Accounts, purchase and
maintenance of Inventory, and transaction costs and expenses associated with
this Agreement and the transactions contemplated hereby) and otherwise for
working capital and general company or corporate purposes of the Borrower and
the Subsidiaries. Borrower will not, directly or indirectly, use any part of
such proceeds for (a) any other purpose or purposes, including the purpose of
purchasing or carrying any margin stock within the meaning of Regulation U of
the Board of Governors of the Federal Reserve System or to extend credit to any
Person for the purpose of purchasing or carrying any such margin stock, or for
any purpose which violates, or is inconsistent with, Regulation X of such Board
of Governors.


                                       11

<PAGE>

     SECTION 2.10. LETTER OF CREDIT FACILITY.

          (1) LETTERS OF CREDIT. On the terms and conditions hereinafter set
forth, the Commitment may be used by Borrower, at its request, for the issuance
of a Letter of Credit, on Borrower's account, pursuant to the Bank's customary
policies and in accordance with the terms and provisions of the Bank's
standardized documents, to be executed and delivered to the Bank at the time of
issuance of each such Letter of Credit, in amounts outstanding at no time
exceeding Ten Million and No/100ths Dollars ($10,000,000.00) in the aggregate,
provided, however, in no event shall a Letter of Credit be issued which together
with the then outstanding Loans exceeds the Commitment. The expiry of each such
Letter of Credit shall be no later than the earlier of (a) sixty (60) days prior
to the Maturity Date or (b) one (1) year from initial issuance thereof. In the
event that the expiry of any Letter of Credit is later than either (A) the date
the repayment of the Obligations is owed due to the acceleration thereof by the
Bank or (B) the Maturity Date, the Bank may require such outstanding Letter of
Credit to be one hundred and ten percent (110%) cash collateralized. Upon the
termination of any such Letter of Credit and provided no Event of Default then
exists and is continuing, the portion of such cash collateral attributable to
the undrawn portion of such Letter of Credit shall be refunded to Borrower.

          (2) REIMBURSEMENT OBLIGATION OF BORROWER. If the Bank shall honor any
draw request under, and make payment in respect of, any Letter of Credit, (a)
Borrower shall reimburse the Bank for the amount of such payment by the end of
the Business Day on which the Bank makes such payment and (b) Borrower shall be
deemed to have immediately requested that a Loan be made to it in the amount
equal to the amount of such payment (but solely to the extent Borrower shall
have failed to directly reimburse the Bank for the amount of such payment). To
the extent that such Loan shall cause the Borrower to exceed the Borrowing Base,
Borrower shall forthwith pay the Bank sufficient funds to reduce the balance of
the Operating Note.

          (3) RISK REGARDING LETTER OF CREDIT. The Bank shall not be responsible
in any way for (a) the performance of any beneficiary under any Letter of Credit
of that beneficiary's obligations to the Borrower or (b) the form, sufficiency,
correctness, genuineness, or authority of any person signing, falsification or
the legal effect of any documents called for under any Letter of Credit if (with
respect to the foregoing) such documents on their face appear to be in order.
All directions, correspondence, and fund transfers relating to any Letters of
Credit are at the sole risk of the Borrower. The obligations of the Borrower to
reimburse the Bank regarding any Letter of Credit shall be absolute,
unconditional and irrevocable and shall be performed, under all circumstances
whatsoever, including the following: (x) any lack of validity or enforceability
of, or any amendment or waiver of or any consent to departure from, any Letter
of Credit or any related document thereto; (y) the existence of any claim,
set-off, defense or other right which Borrower may have at any time against the
beneficiary of any Letter of Credit; or (z) to the extent permitted under
applicable law, any other circumstance or happening whatsoever, whether or not
similar to any of the foregoing.

     SECTION 2.11. CLOSING. The closing under this Agreement shall take place at
the Principal Office of the Bank upon (a) execution of this Agreement by the
Borrower, each of the Restricted Subsidiaries and the Bank and (b) satisfaction
of each of the Initial Conditions Precedent.


                                       12

<PAGE>

                                   ARTICLE III

                              CONDITIONS PRECEDENT

     SECTION 3.01. CONDITION PRECEDENT TO LOANS. The obligation of the Bank to
make initial Loans to the Borrower pursuant to the Commitment is subject to the
conditions precedent that the Bank shall have received, or waived in writing the
obligation to receive, on or before the Closing Date each of the following, in
form and substance satisfactory to the Bank and its counsel (collectively the
"Initial Conditions Precedent"):

          (1) OPERATING NOTE. The Operating Note duly executed by the Borrower;

          (2) SECURITY AGREEMENT. The Security Agreement duly executed by the
Borrower together with certified copies of Request for Copies or Information
(Form UCC-11) identifying all of the financing statements on file with respect
to the Borrower, indicating that no party claims an interest in any of the
Collateral;

          (3) CONTROL AGREEMENT. The Control Agreement duly executed by the
Borrower;

          (4) EVIDENCE OF ALL COMPANY ACTION BY THE BORROWER AND THE RESTRICTED
SUBSIDIARIES. Certified (as of the Closing Date) copies of all company action
taken by the Borrower and the Restricted Subsidiaries, including resolutions of
the respective Boards of Directors, Members or Managers as necessary,
authorizing the execution, delivery, and performance of the Loan Documents to
which it is a party and each other document to be delivered pursuant to this
Agreement;

          (5) INCUMBENCY AND SIGNATURE CERTIFICATE OF THE BORROWER AND THE
RESTRICTED SUBSIDIARIES. A certificate (dated as of the Closing Date) of the
Secretary, or the manager, or such other officer (acceptable to the Bank), as
the case may be, of the Borrower and of each of the Restricted Subsidiaries
certifying the names and true signatures of the Authorized Person(s) of the
Borrower and of each of the Restricted Subsidiaries, respectively, authorized to
sign the Loan Documents to which it is a party and the other documents to be
delivered by the Borrower and the Restricted Subsidiaries under this Agreement;

          (6) OPINION OF COUNSEL FOR THE BORROWER. A favorable opinion of (a)
Stoel Rives, LLP, outside corporate counsel to the Borrower and the Restricted
Subsidiaries, in the form attached hereto as Exhibit "O" and incorporated herein
by this reference, and (b) Cadwell Sanford Deibert & Garry LLP, South Dakota and
Nebraska counsel to the Borrower and the Restricted Subsidiaries, in the form
attached hereto as Exhibit "P" and incorporated herein by this reference;

          (7) SUBSIDIARY GUARANTIES. The Subsidiary Guaranties duly executed and
acknowledged by each of the Restricted Subsidiaries;


                                       13

<PAGE>

          (8) SUBSIDIARY SECURITY AGREEMENTS. The Subsidiary Security Agreements
duly executed by each of the Restricted Subsidiaries together with certified
copies of Request for Copies or Information (Form UCC-11) identifying all of the
financing statements on file with respect to the Restricted Subsidiary,
indicating that no party claims an interest in any of the Collateral;

          (9) SUBSIDIARY CONTROL AGREEMENT. The Control Agreement duly executed
by each of the Restricted Subsidiaries;

          (10) CLOSING FEE. Payment of the Closing Fee;

          (11) PAYMENT OF OTHER OBLIGATIONS OF RESTRICTED SUBSIDIARIES TO BANK.
On the Closing Date, the proceeds of the Senior Secured Notes of the Borrower
shall have been utilized to pay-in-full, and payment thereof shall have been
received by the Bank, of all existing obligations of Aurora and Fort Dodge to
the Bank; and

          (12) SECURED NOTE DOCUMENTS. On the Closing Date, the Bank shall have
received a copy of the Senior Secured Notes and each of the Senior Note
Documents, certified as true and correct by the chief financial officer of the
Borrower.

     SECTION 3.02. CONDITIONS PRECEDENT TO ADDITIONAL LOANS. The obligation of
the Bank to make Loans to the Borrower pursuant to the Commitment following the
Closing Date shall be subject to the further conditions precedent that on the
date of such Loan (the "Additional Conditions Precedent"):

          (1) The following statements shall be true and the Bank shall have
received a certificate signed by an Authorized Person dated the date of such
Loan, stating that:

                    (a) The Conditions Precedent contained in Section 3.01 of
               this Agreement have been complied with by the Borrower and each
               Restricted Subsidiary in all respects;

                    (b) The representations and warranties contained in (i)
               Article IV of this Agreement, (ii) the Security Agreement of the
               Borrower, (iii) each of the Subsidiary Security Agreements, and
               (iv) each of the Control Agreements, are true and correct on and
               as of the date of such Loan as though made on and as of such
               date, instead of the Closing Date; and

                    (c) No Default or Event of Default has occurred and is
               continuing, or would result from such Loan; and

          (2) The Bank shall have received such other documents as the Bank may
reasonably request.


                                       14

<PAGE>

                                   ARTICLE IV

                         REPRESENTATIONS AND WARRANTIES

     The Borrower and each Restricted Subsidiary jointly represents and warrants
to the Bank that:

     SECTION 4.01. ORGANIZATION, GOOD STANDING, AND DUE QUALIFICATION. The
Borrower and each Restricted Subsidiary is a corporation or limited liability
company duly organized, validly existing, and in good standing under the laws of
the State of its formation; has the power and authority to own its assets and to
transact the business in which it is now engaged or proposed to be engaged in;
and is duly qualified as a foreign corporation or limited liability company, as
the case may be, and in good standing under the laws of each other jurisdiction
in which such qualification is required, except where the failure to be
qualified and in good standing would not have a material adverse effect on
Borrower and the Restricted Subsidiaries taken as a whole.

     SECTION 4.02. POWER AND AUTHORITY. The execution, delivery, and performance
by the Borrower and each Restricted Subsidiary of the Loan Documents to which
each is a party have been duly authorized by all necessary action and do not and
will not (1) require any consent or approval of the shareholders of Borrower or
the shareholder or members of any Restricted Subsidiary which has not previously
been obtained; (2) contravene Borrower's or any Restricted Subsidiary's
Organizational Documents; (3) violate any provision of any law, rule, regulation
(including, without limitation, Regulations U and X of the Board of Governors of
the Federal Reserve System), order, writ, judgment, injunction, decree,
determination, or award presently in effect having applicability to Borrower or
any Restricted Subsidiary; (4) result in a breach of or constitute a default
under any indenture or loan or credit agreement or any other material agreement,
lease, or instrument to which Borrower or any Restricted Subsidiary is a party
or by which it or its properties may be bound or affected; or (5) result in, or
require, the creation or imposition of any Lien, upon or with respect to any of
the Collateral now owned or hereafter acquired by Borrower or any Restricted
Subsidiary (except in favor of the Bank).

     SECTION 4.03. LEGALLY ENFORCEABLE AGREEMENT. This Agreement is, and each of
the other Loan Documents when delivered under this Agreement will be, legal,
valid, and binding obligations of the Borrower and the Restricted Subsidiaries,
as the case may be, and enforceable against the Borrower or the Restricted
Subsidiaries, as the case may be, in accordance with their respective terms,
except to the extent that such enforcement may be limited by applicable
bankruptcy, insolvency, and other similar laws affecting creditors' rights
generally.

     SECTION 4.04. PROVIDED INFORMATION. No information, exhibit, or report
furnished by the Borrower or any Restricted Subsidiary to the Bank in connection
with the negotiation of this Agreement contained or contains any material
misstatement of fact, or omitted or omits to state a material fact or any fact
necessary to make the statement contained therein not materially misleading.


                                       15

<PAGE>

     SECTION 4.05. OTHER AGREEMENTS. Neither the Borrower nor any Restricted
Subsidiary is a party to any indenture, loan, or credit agreement, or to any
lease or other agreement or instrument, or subject to any charter or restriction
which could have a material adverse effect on the ability of the Borrower or any
Restricted Subsidiary to carry out its obligations under the Loan Documents to
which it is a party. Neither the Borrower nor any Restricted Subsidiary is in
default in any material respect in the performance, observance, or fulfillment
of any of the obligations, covenants, or conditions contained in any agreement
or instrument material to its business to which it is a party.

     SECTION 4.06. NO RESTRICTION ON DIVIDENDS OR DISTRIBUTIONS. None of the
Restricted Subsidiaries is subject to any restriction, nor shall the Borrower
cause or permit any restriction to exist, which limits the ability of such
Restricted Subsidiary to pay dividends to the Borrower or otherwise make
distributions to the Borrower, except as provided under applicable law.

     SECTION 4.07. LITIGATION OR PROCEEDINGS. There is no pending or, to the
Borrower's or any Restricted Subsidiaries' knowledge, threatened action or
proceeding against or affecting the Borrower or any of its Restricted
Subsidiaries before any court, governmental agency, or arbitrator which may, in
any one case or in the aggregate, materially adversely affect the financial
condition, operations, properties, or business of the Borrower and its
Restricted Subsidiaries, taken as a whole, or the ability of the Borrower and
its Restricted Subsidiaries, taken as a whole, to perform their obligations
under the Loan Documents to which it is a party.

     SECTION 4.08. NO DEFAULTS ON OUTSTANDING JUDGMENTS OR ORDERS. The Borrower
and its Subsidiaries have satisfied all final non-appealable judgments and
neither the Borrower nor any Subsidiary is in default with respect to any
judgment, writ, injunction, decree, rule, or regulation of any court,
arbitrator, or federal, state, municipal, or other governmental authority,
commission, board, bureau, agency or instrumentality, domestic or foreign.

     SECTION 4.09. OWNERSHIP AND LIENS. As of the date hereof, the Borrower is
the owner of one hundred percent (100%) of the issued and outstanding equity
interest (stock or membership interest) in each of the Subsidiaries listed on
Exhibit "S." The Borrower and each Restricted Subsidiary have title to, or valid
leasehold interests in, all of their respective properties and assets, real and
personal (other than any properties or assets disposed of in the ordinary course
of business), and none of the properties and assets owned by the Borrower or any
Restricted Subsidiary and none of the Borrower's or any Restricted Subsidiary's
leasehold interests are subject to any lien, mortgage, deed of trust, pledge,
security interest, or other charge or encumbrance of any nature except as such
as may be permitted, and only to the extent permitted, under this Agreement and
the Senior Note Documents.

     SECTION 4.10. SUBSIDIARIES. As of the date hereof, Borrower has no
Subsidiaries other than the Current Subsidiaries. Set forth in Exhibit "S" is a
complete and accurate list of the Subsidiaries of the Borrower, showing the type
of entity and jurisdiction of formation of each and showing the percentage of
the Borrower's ownership interest of each Subsidiary. All equity ownership
interests of each Restricted Subsidiary have been validly issued, are fully paid
and nonassessable, and are owned by the Borrower free and clear of all Liens.


                                       16

<PAGE>

     SECTION 4.11. OPERATION OF BUSINESS. The Borrower and its Restricted
Subsidiaries possess all material licenses, permits, franchises, patents,
copyrights, trademarks, and trade names, or rights thereto, to conduct their
respective businesses substantially as now conducted and as presently proposed
to be conducted, and neither the Borrower nor any of its Restricted Subsidiaries
is in violation in any material respect of any valid rights of others with
respect to any of the foregoing; provided, however, that Charles City has only
such licenses and permits as are required with respect to its current stage of
development.

     SECTION 4.12. REPRESENTATION AND WARRANTIES TO OTHERS. As of the date
hereof, each of the representations and warranties of the Borrower and each of
the Subsidiaries made in or relating to the Senior Secured Notes or any of the
Senior Note Documents, are true and correct in all material respects.

                                    ARTICLE V

                        BORROWER'S AFFIRMATIVE COVENANTS

     So long as the Operating Note or any Letter of Credit shall remain unpaid
or the Bank shall have any Commitment under this Agreement, the Borrower will:

     SECTION 5.01. MAINTENANCE OF EXISTENCE. Preserve and maintain, and cause
each Restricted Subsidiary to preserve and maintain, its
corporate/organizational existence and good standing in the jurisdiction of its
incorporation/organization, and qualify and remain qualified, and cause each
Restricted Subsidiary to qualify and remain qualified, as a foreign
corporation/limited liability company in each jurisdiction in which such
qualification is required, except where the failure to be qualified and in good
standing would not have a material adverse effect on Borrower and the
Subsidiaries taken as a whole.

     SECTION 5.02. MAINTENANCE OF RECORDS. Keep, and cause each Restricted
Subsidiary to keep, adequate records and books of account, in which complete
entries will be made in accordance with GAAP consistently applied, reflecting
all financial transactions of the Borrower and its Restricted Subsidiaries.

     SECTION 5.03. MAINTENANCE OF PROPERTIES. Maintain, keep, and preserve, and
cause each Restricted Subsidiary to maintain, keep, and preserve, all of its
properties (tangible and intangible) necessary or useful in the proper conduct
of its business in good working order and condition, ordinary wear and tear
excepted and except for properties or assets disposed of or sold in the ordinary
course of business or in accordance with the Senior Note Documents.

     SECTION 5.04. CONDUCT OF BUSINESS. Continue, and cause each Restricted
Subsidiary to continue, to engage in a business of the same general type as
conducted or planned to be conducted by it on the date of this Agreement.

     SECTION 5.05. MAINTENANCE OF INSURANCE. Maintain, and cause each Restricted
Subsidiary to maintain, insurance with financially sound and reputable insurance
companies or associations


                                       17

<PAGE>

in such amounts and covering such risks as are usually carried by companies
engaged in the same or a similar business and similarly situated, which
insurance may provide for reasonable deductibility from coverage thereof.

     SECTION 5.06. COMPLIANCE WITH LAWS. Comply, and cause each Subsidiary to
comply, in all material respects with all applicable laws, rules, regulations,
and orders relating to the operation of its business, except where the failure
to comply would not have a material adverse effect on the Borrower and the
Restricted Subsidiaries taken as a whole.

     SECTION 5.07. RIGHT OF INSPECTION. At any reasonable time and from time to
time, at the Borrower's sole cost and expense (provided that Borrower shall only
be obligated to pay the cost and expense of an inspection by the Bank as
provided hereunder twice per calendar year, unless a Default or an Event of
Default exists at the time of such inspection), and upon a least five (5) days
prior written notice, permit the Bank or any agent or representative thereof to
examine and make copies of and abstracts from the records and books of account
of, and visit the properties of, the Borrower and any Subsidiary, and to discuss
the affairs, finances, and accounts of the Borrower and any Subsidiary with any
of their respective officers, managers, and directors.

     SECTION 5.08. FINANCIAL COVENANTS. As of the end of respective each
calendar quarter, maintain Minimum Tangible Net Worth and Minimum Working
Capital.

     SECTION 5.09. REPORTING REQUIREMENTS. Furnish to the Bank:

          (1) QUARTERLY FINANCIAL STATEMENTS. As soon as available and in any
event within thirty (30) days after the end of each calendar quarter following
the Closing Date, consolidated balance sheets of the Borrower and its
Subsidiaries, including a consolidating schedule relating thereto, as of the end
of such calendar quarter, consolidated statements of income and shareholders'
equity of the Borrower and its Subsidiaries, including a consolidating schedule
of each relating thereto, for the period commencing at the end of the previous
fiscal year and ending with the end of such calendar quarter, all in reasonable
detail and stating in comparative form the respective figures for the
corresponding date and period in the previous fiscal year and all prepared in
accordance with GAAP consistently applied, except for the absence of financial
footnotes, and certified by the chief financial officer of the Borrower;

          (2) ANNUAL FINANCIAL STATEMENTS. As soon as available and in any event
within one hundred twenty (120) days after the end of each fiscal year of the
Borrower, consolidated balance sheets of the Borrower and its Subsidiaries,
including a consolidating schedule relating thereto, as of the end of such
fiscal year and consolidated statements of income of the Borrower and its
Subsidiaries, including a consolidating schedule relating thereto, for such
fiscal year, and consolidated statements of shareholders' equity of the Borrower
and its Subsidiaries, including a consolidating schedule relating thereto, for
such fiscal year, all in reasonable detail and stating in comparative form the
respective figures for the corresponding date and period in the prior fiscal
year and all prepared in accordance with GAAP consistently applied and
accompanied by an opinion thereon acceptable to the Bank by independent
certified public accountants selected by the Borrower and reasonably acceptable
to the Bank;


                                       18

<PAGE>

          (3) ANNUAL PROJECTED FINANCIAL STATEMENTS. As soon as available and in
any event at least thirty (30) days prior to the end of each fiscal year of the
Borrower, projected consolidated and consolidating financial statement of the
Borrower and the Subsidiaries for the next succeeding fiscal year, including
proposed capital projects and capital expenditures;

          (4) QUARTERLY CONSOLIDATED AND CONSOLIDATING PRODUCTION REPORT. As
soon as available and in any event within thirty (30) days after the end of each
calendar quarter following the Closing Date, consolidated and consolidating
production reports of the Borrower and its Restricted Subsidiaries, in the form
attached hereto as Exhibit "T" and incorporated herein by this reference, and
certified by an Authorized Person;

          (5) BORROWING BASE CERTIFICATE. As soon as available and in any event
within ten (10) days after the end of each month following the Closing Date, a
Borrowing Base Certificate as of the end of such month, and certified by an
Authorized Person;

          (6) CERTIFICATE OF COMPLIANCE. Within thirty (30) days after the end
of each of calendar quarter following the Closing Date, a certificate of the
chief financial officer of the Borrower certifying that the Borrower and each of
the Restricted Subsidiaries is in compliance with the terms and provisions of
this Agreement, including the financial covenants contained herein, and that to
the best of the chief financial officer's knowledge no Default or Event of
Default has occurred and is continuing or, if a Default or Event of Default has
occurred and is continuing, a statement as to the nature thereof and the action
which is proposed to be taken with respect thereto;

          (7) NOTICE OF LITIGATION. Promptly after the Borrower has been served
with notice thereof, notice of all actions, suits, and proceedings before any
court or governmental department, commission, board, bureau, agency, or
instrumentality, domestic or foreign, affecting the Borrower or any Subsidiary,
which, if determined adversely to the Borrower or such Subsidiary, could have a
material adverse effect on the financial condition, properties, or operations of
the Borrower or any Subsidiary taken as a whole;

          (8) NOTICE OF DEFAULTS AND EVENTS OF DEFAULT. As soon as possible and
in any event within five (5) days after Borrower's or any Restricted
Subsidiary's management becoming aware of the occurrence of each Default or
Event of Default, a written notice setting forth the details of such Default or
Event of Default and the action which is proposed to be taken by the Borrower
with respect thereto;

          (9) PROXY STATEMENTS, ETC. Promptly after the sending or filing
thereof, copies of all proxy statements, financial statements, and reports which
the Borrower or any Subsidiary sends to its stockholders, members, or partners,
and copies of all regular, periodic, and special reports, and all registration
statements which the Borrower or any Subsidiary files with the Securities and
Exchange Commission or any governmental authority which may be substituted
therefor, or with any national securities exchange; and


                                       19

<PAGE>

          (10) GENERAL INFORMATION. Such other information respecting the
condition or operations, financial or otherwise, of the Borrower or any
Subsidiary as the Bank may from time to time reasonably request.

     SECTION 5.10. COMPLIANCE WITH LAW AND REGULATIONS. Be and remain, and cause
each Subsidiary to be and remain, in compliance in all material respects with
all law, regulations and rules relating to the operation of the businesses of
the Borrower and its Subsidiaries; notify the Bank immediately of any written
notice of any material violation thereof and the action which is proposed to be
taken with respect thereto; permit the Bank to inspect all books,
correspondence, and records pertaining thereto; and at the Bank's request, and
at the Borrower's expense, provide a report of a qualified consultant,
satisfactory in scope, form, and content to the Bank, and such other and further
assurances reasonably satisfactory to the Bank that the condition has been
corrected.

     SECTION 5.11. COLLATERAL DEPOSIT ACCOUNTS. Cause all proceeds of the
Collateral under the Security Agreement and Subsidiary Security Agreements to be
deposited in, and only in, deposit accounts at the Bank or in accounts which are
the subject of the respective Control Agreements.

     SECTION 5.12. OTHER COVENANTS. Comply with, and cause each of the
Subsidiaries to comply with, their respective covenants and obligations under or
pursuant to the Senior Secured Notes or any of the Senior Note Documents.

     SECTION 5.13. REPLACEMENT OF EXISTING LETTERS OF CREDIT. Immediately
following the Closing Date and in no event later than sixty (60) days following
the Closing Date, cause each of the Restricted Subsidiaries to replace each of
the letters of credit issued by the Bank for the benefit of such Restricted
Subsidiary as of the date of this Agreement with a Letter of Credit issued by
the Bank under the Letter of Credit Facility and return the original of each
such existing letter of credit to the Bank.

                                   ARTICLE VI

                               NEGATIVE COVENANTS

     So long as the Operating Note shall remain unpaid, any Letter of Credits
issued pursuant to the Letter of Credit Facility are outstanding, or the Bank
shall have any Commitment under this Agreement, the Borrower will not, without
the prior written consent of the Bank in each instance:

     SECTION 6.01. LIENS. Create, incur, assume, or suffer to exist, or permit
any Restricted Subsidiary to create, incur, assume, or suffer to exist, any Lien
upon or with respect to any of the Collateral, whether or not subordinate to the
interest therein provided to the Bank.

     SECTION 6.02. MERGERS, ETC. Wind up, liquidate or dissolve itself,
reorganize, merge or consolidate with or into, or convey, sell, assign,
transfer, lease, or otherwise dispose of (whether in one transaction or in a
series of transactions) all or substantially all of its assets (whether now
owned or hereafter acquired) to any Person, or acquire all or substantially all
of the assets or the business of any Person, or permit any Restricted Subsidiary
to do so.


                                       20

<PAGE>

     SECTION 6.03. COLLATERAL ACTION. Take any action, or allow any Restricted
Subsidiary to take any action, which is intended to, or the effective of which
may be to, restrict or negatively impact the Bank's security interest in and to
the Collateral.

     SECTION 6.04. DISTRIBUTIONS. Take any action or allow any Restricted
Subsidiary to take any action which may have the effect of restricting the
ability of the Restricted Subsidiary to pay dividends or otherwise make
distributions to the Borrower.

     SECTION 6.05. ADDITIONAL SUBSIDIARIES. Permit, or allow any Subsidiary to
permit, any Additional Subsidiary to commence construction of or operate an
ethanol production facility, unless the Borrower notifies the Bank at least ten
(10) days prior to such construction or operation and causes such Additional
Subsidiary to (a) become a Restricted Subsidiary and (b) execute and deliver to
the Bank, the following immediately following such notification: (1) a
Subsidiary Guaranty substantially consistent with the terms and provisions of
the Exhibits hereto relating to Subsidiary Guaranties; (2) a Subsidiary Security
Agreement substantially consistent with the terms and provisions of the Exhibits
hereto relating to Subsidiary Security Agreements; (3) certified copies of
Request for Copies or Information (Form UCC-11) identifying all of the financing
statements on file with respect to the respective Additional Subsidiary,
indicating that no party claims an interest in any of the Collateral; (4) a
Control Agreement substantially consistent with the terms and provisions of the
Exhibits hereto relating to a Control Agreement; (5) a certificate of the
Secretary, manager, or managing partner (as applicable) of such Additional
Subsidiary certifying the names and true signatures of the officers or manager
of the Additional Subsidiary authorized to sign such Loan Documents to which it
is a party; and (6) copies of the executed Organization Documents certified by
the Secretary, manager, or managing partner (as applicable) of such Additional
Subsidiary to be true and correct.

     6.06. UNRESTRICTED SUBSIDIARIES. Cause or allow any Unrestricted Subsidiary
to be in the business of the production of ethanol similar to a Restricted
Subsidiary without electing to have such Subsidiary be deemed a Restricted
Subsidiary and complying with the terms and provisions of Section 6.05 relating
thereto.

                                   ARTICLE VII

                                EVENTS OF DEFAULT

     SECTION 7.01. EVENTS OF DEFAULT. If any of the following events shall
occur:

          (1) The Borrower should fail to pay the principal of, or interest on,
the Note or other fees, costs or expenses relating to the transactions provided
for in any of the Loan Documents within ten (10) days of the date when such
amount is due and payable;

          (2) Any representation or warranty made or deemed made by the Borrower
in this Agreement, the Security Agreement or the Control Agreement, or by a
Subsidiary Guarantor in this Agreement, any of the Subsidiary Guaranties, any of
the Subsidiary Security Agreements, or any of the Subsidiary Control Agreements
or which is contained in any certificate, document,


                                       21

<PAGE>

opinion, or financial or other statement furnished at any time under or in
connection with any Loan Document shall prove to have been incorrect,
incomplete, or misleading in any material respect on or as of the date made or
deemed made;

          (3) The Borrower shall fail to perform or observe any term, covenant,
or agreement made by the Borrower in this Agreement, the Security Agreement, the
Control Agreement, or any other agreement or undertaking by the Borrower
pursuant to or relating to the terms and provisions of this Agreement, and such
failure continues for thirty (30) days after written notice to the Borrower;

          (4) A Subsidiary Guarantor shall fail to perform or observe any term,
covenant, or agreement made by such Subsidiary Guarantor in this Agreement, a
Subsidiary Guaranty, a Subsidiary Security Agreement, a Subsidiary Control
Agreement or any other agreement or undertaking by a Subsidiary Guarantor
pursuant to or relating to the terms and provisions of this Agreement, and such
failure continues for thirty (30) days after written notice to the Borrower;

          (5) The Borrower or any of its Restricted Subsidiaries shall (a) fail
to pay any indebtedness for borrowed money in excess of Two Hundred Fifty
Thousand Dollars ($250,000.00)(other than the Operating Note) of the Borrower or
such Restricted Subsidiary, as the case may be, when due (whether by scheduled
maturity, required prepayment, acceleration, demand, or otherwise), including
but not limited to the Senior Secured Notes, or (b) fail to perform or observe
any term, covenant, or condition on its part to be performed or observed under
any agreement or instrument, including but not limited to the Senior Secured
Notes or any of the Senior Note Documents, relating to any such indebtedness,
when required to be performed or observed, if the effect of such failure to
perform or observe is to accelerate, or to permit the acceleration of, after the
giving of notice or passage of time, or both, the maturity of such indebtedness,
if such failure to perform or observe shall not have been waived by the holder
of such indebtedness; or any such indebtedness shall be declared to be due and
payable, or required to be prepaid (other than by a regularly scheduled required
prepayment), prior to the stated maturity thereof;

          (6) The Borrower or any of its Restricted Subsidiaries or any
Subsidiary Guarantor (a) shall generally not pay, or shall be unable to pay, or
shall admit in writing its inability to pay its debts as such debts become due;
or (b) shall make an assignment for the benefit of creditors, or petition or
apply to any tribunal for the appointment of a custodian, receiver, or trustee
for it or a substantial part of its assets; or (c) shall commence any proceeding
under any bankruptcy, reorganization, arrangement, readjustment of debt,
dissolution, or liquidation law or statute of any jurisdiction, whether now or
hereafter in effect; or (d) shall have had any such petition or application
filed or any such proceeding commenced against it in which an order for relief
is entered or an adjudication or appointment is made, and which remains
undismissed for a period of sixty (60) days or more; or (e) shall take any
action indicating its consent to, approval of, or acquiescence in any such
petition, application, proceeding, or order for relief or the appointment of a
custodian, receiver, or trustee for all or any substantial part of its
properties; or (f) shall suffer any such custodianship, receivership, or
trusteeship to continue undischarged for a period of sixty (60) days or more;


                                       22

<PAGE>

          (7) One or more judgments, decrees, or orders for the payment of money
in excess of Two Hundred Fifty Thousand and No/100ths Dollars ($250,000.00) in
the aggregate shall be rendered against the Borrower or any of its Restricted
Subsidiaries and such judgments, decrees, or orders shall continue unsatisfied
and in effect for a period of thirty (30) consecutive days without being
vacated, discharged, satisfied, or stayed or bonded pending appeal;

          (8) The Security Agreement and each Subsidiary Security Agreement
shall at any time after its execution and delivery and for any reason cease (a)
to create a valid and perfected first priority security interest in and to the
Collateral purported to be subject to such Security Agreement or Subsidiary
Security Agreement; or (b) to be in full force and effect or shall be declared
null and void, or the validity or enforceability thereof shall be contested by
the Borrower or any Restricted Subsidiary, or the Borrower or any Restricted
Subsidiary shall deny it has any further liability or obligation under the
Security Agreement or any Subsidiary Security Agreement, or the Borrower or
Restricted Subsidiary shall fail to perform any of its obligations under the
Security Agreement or Subsidiary Security Agreement;

          (9) The Control Agreement and each Subsidiary Control Agreement shall
at any time after its execution and delivery and for any reason cease (a) to
create a valid and perfected first priority security interest in and to the
Collateral purported to be subject to such Control Agreement or Subsidiary
Control Agreement; or (b) to be in full force and effect or shall be declared
null and void, or the validity or enforceability thereof shall be contested by
the Borrower or any Restricted Subsidiary, or the Borrower or any Restricted
Subsidiary shall deny it has any further liability or obligation under the
Control Agreement or any Subsidiary Control Agreement, or the Borrower or
Restricted Subsidiary shall fail to perform any of its obligations under the
Control Agreement or Subsidiary Control Agreement; or

          (10) Any Guaranty shall at any time after its execution and delivery
and for any reason cease to be in full force and effect or shall be declared
null and void, or the validity or enforceability thereof shall be contested by
any Subsidiary Guarantor or any Subsidiary Guarantor shall deny it has any
further liability or obligation under, or shall fail to perform its obligations
under, such Subsidiary Guarantor's Guaranty.

     Then, and in any such event, the Bank may, by written notice to the
Borrower, (1) declare its Commitment to make Loans to be terminated, whereupon
the same shall forthwith terminate, (2) declare the Operating Note, all interest
thereon, and all other amounts payable under this Agreement or the Note to be
forthwith due and payable, whereupon the Operating Note, all such interest, and
all such amounts shall become and be forthwith due and payable, without
presentment, demand, protest, or further notice of any kind, all of which are
hereby expressly waived by the Borrower, to the extent permitted by applicable
law, and (3) take any and all action reasonably required by the Bank to limit
and restrict the exposure of the Bank relating to any then outstanding Letters
of Credit provided pursuant to the Letter of Credit Facility, without
presentment, demand, protest, or further notice of any kind, all of which are
hereby expressly waived by the Borrower, to the extent permitted by applicable
law.


                                       23

<PAGE>

     Upon the occurrence and during the continuance of any Event of Default, the
Bank is hereby authorized at any time and from time to time, without written
notice to the Borrower or any Subsidiary (any such notice being expressly waived
by the Borrower), to set off and apply any and all deposits (general or special,
time or demand, provisional or final) at any time held and other indebtedness at
any time owing by the Bank to or for the credit or the account of the Borrower
or any Subsidiary against any and all of the obligations of the Borrower now or
hereafter existing under this Agreement or the Note or any other Loan Document,
irrespective of whether or not the Bank shall have made any demand under this
Agreement or the Note or such other Loan Document and although such obligations
may be unmatured. The Bank agrees promptly to notify the Borrower after any such
setoff and application, provided that the failure to give such notice shall not
affect the validity of such setoff and application. The rights of the Bank under
this Section 7.01 are in addition to other rights and remedies (including,
without limitation, other rights of setoff) which the Bank may have.

                                  ARTICLE VIII

                                  MISCELLANEOUS

     SECTION 8.01. AMENDMENTS, ETC. No amendment, modification, termination, or
waiver of any provision of any Loan Document, nor consent to any departure from
any provision of any of the Loan Documents, shall in any event be effective
unless the same shall be in writing and signed by the Bank, and then such waiver
or consent shall be effective only in the specific instance and for the specific
purpose for which given.

     SECTION 8.02. NOTICES, ETC. All notices and other communications provided
for under this Agreement and under the other Loan Documents to which the
Borrower is a party shall be in writing (including facsimile transmissions) and
mailed or transmitted or delivered, if to the Borrower, at its address at 100
22nd Ave., Brooking, South Dakota 57006, Attention: Bruce Jamerson, and if to
the Bank, at its address at 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197,
Attention: Natalie E. Mason; or, as to each party, at such other address as
shall be designated by such party in a written notice to the other party
complying as to delivery with the terms of this Section 8.02. Except as
otherwise provided in this Agreement, all such notices and communications shall
be effective when deposited in the mails, or sent, answerback received,
respectively, addressed as aforesaid.

     SECTION 8.03. NO WAIVER. No failure or delay on the part of the Bank in
exercising any right, power, or remedy hereunder shall operate as a waiver
thereof; nor shall any single or partial exercise of any such right, power, or
remedy preclude any other or further exercise thereof or the exercise of any
other right, power, or remedy hereunder. The rights and remedies provided herein
are cumulative, and are not exclusive of any other rights, powers, privileges,
or remedies, now or hereafter existing, at law or in equity or otherwise.

     SECTION 8.04. SUCCESSORS AND ASSIGNS. This Agreement shall be binding upon
and inure to the benefit of the Borrower, the Subsidiaries, and the Bank and
their respective successors and assigns, except that neither the Borrower nor
any of the Subsidiaries may assign or transfer any


                                       24

<PAGE>

of its rights or obligations under this Agreement or any Loan Document to which
it is a party without the prior written consent of the Bank.

     SECTION 8.05. COSTS, EXPENSES, AND TAXES. The Borrower agrees to pay on
demand all costs and expenses incurred by the Bank in connection with the
preparation, execution, delivery, filing, and administration of the Loan
Documents, and of any amendment, modification, or supplement to the Loan
Documents, including, without limitation, the reasonable fees and reasonable
out-of-pocket expenses of counsel for the Bank incurred in connection with
advising the Bank as to its rights and responsibilities hereunder. The Borrower
also agrees to pay all such costs and expenses, including court costs, incurred
in connection with enforcement of the Loan Documents, or any amendment,
modification, or supplement thereto, whether by negotiation, legal proceedings,
or otherwise. In addition, the Borrower shall pay any and all stamp and other
taxes and fees payable or determined to be payable in connection with the
execution, delivery, filing, and recording of any of the Loan Documents and the
other documents to be delivered under any such Loan Documents, and agrees to
hold the Bank harmless from and against any and all liabilities with respect to
or resulting from any delay in paying or omission to pay such taxes and fees.
This provision shall survive termination of this Agreement.

     SECTION 8.06. INTEGRATION. This Agreement and the Loan Documents contain
the entire agreement among the parties relating to the subject matter hereof and
supersede all oral statements and prior writings with respect thereto.

     SECTION 8.07. INDEMNITY. The Borrower and each of the Restricted
Subsidiaries hereby agrees to defend, indemnify, and hold the Bank harmless from
and against any and all claims, damages, judgments, penalties, costs, and
expenses (including reasonable attorney fees and court costs now or hereafter
arising from the aforesaid enforcement of this clause) arising directly or
indirectly from the activities of the Borrower and its Subsidiaries, or arising
directly from (i) the violation of any laws, regulations or rules relating to
the operations of the business of the Borrower or the Subsidiaries, or (ii) the
occurrence of any Default or Event of Default hereunder. This indemnity shall
survive termination of this Agreement, except for any indemnification obligation
which arises based upon the Bank's gross negligence, willful misconduct or
violation of applicable law.

     SECTION 8.08. GOVERNING LAW. This Agreement, the Operating Note and the
remainder of the Loan Documents shall be governed by, and construed in
accordance with, the laws of the State of Nebraska without giving effect to any
choice or conflict of law provision or rule (whether of the State of Nebraska or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Nebraska.

     SECTION 8.09. SEVERABILITY OF PROVISIONS. Any provision of any Loan
Document which is prohibited or unenforceable in any jurisdiction shall, as to
such jurisdiction, be ineffective to the extent of such prohibition or
unenforceability without invalidating the remaining provisions of such Loan
Document or affecting the validity or enforceability of such provision in any
other jurisdiction.


                                       25

<PAGE>

     SECTION 8.10. HEADINGS. Article and Section headings in the Loan Documents
are included in such Loan Documents for the convenience of reference only and
shall not constitute a part of the applicable Loan Documents for any other
purpose.

     SECTION 8.11. SUBMISSION TO JURISDICTION; VENUE. The Borrower, each of the
Restricted Subsidiaries and each of the Subsidiary Guarantors hereby submit to
the jurisdiction of any state or federal court sitting in Omaha, Nebraska, in
any action or proceeding arising out of or relating to this Agreement and agree
that all claims in respect of the action or proceeding may be heard and
determined in any such court. The Borrower, each of the Restricted Subsidiaries
and each of the Subsidiary Guarantors also agree not to bring any action or
proceeding arising out of or relating to this Agreement in any other court. The
Borrower, each of the Restricted Subsidiaries and each of the Subsidiary
Guarantors waive any defense of inconvenient forum to the maintenance of any
action or proceeding so brought and waive any bond, surety, or other security
that might be required of the Bank. The Borrower, each of the Restricted
Subsidiaries and each of the Subsidiary Guarantors agree that a final judgment
in any action or proceeding so brought shall be conclusive and may be enforced
by suit on the judgment or in any other manner provided by law or at equity. The
Borrower, each of the Restricted Subsidiaries and each of the Subsidiary
Guarantors hereby waive any rights they may have to transfer or change the venue
of any suit, action or other proceeding brought against the Borrower, any of the
Restricted Subsidiaries or any of the Subsidiary Guarantors by the Bank in
accordance with this Section 8.11 or in connection with this Agreement or any
other Loan Documents.

     SECTION 8.12. JURY TRIAL WAIVER. THE BANK, EACH OF THE RESTRICTED
SUBSIDIARIES, EACH OF THE SUBSIDIARY GUARANTORS AND THE BORROWER HEREBY WAIVE
TRIAL BY JURY IN ANY ACTION, PROCEEDING, CLAIM, OR COUNTERCLAIM, WHETHER IN
CONTRACT OR TORT, AT LAW OR IN EQUITY, ARISING OUT OF OR IN ANY WAY RELATED TO
THIS AGREEMENT OR THE LOAN DOCUMENTS. NO OFFICER OF THE BANK HAS AUTHORITY TO
WAIVE, CONDITION, OR MODIFY THIS PROVISION.

     SECTION 8.13. PARTICIPATIONS. Notwithstanding any other provision of this
Agreement, the Borrower and each Restricted Subsidiary understands that, while
the Bank does not have a current intention to sell participation interests in
the Loans, the Bank reserves the right to enter into participation agreements
with other lenders whereby the Bank will allocate a certain percentage of the
Loans to such other lenders. The Borrower and each Restricted Subsidiary
specifically permit and authorize the Bank to exchange financial information
about the Borrower and the Restricted Subsidiaries with actual or potential
participants. The Borrower and the Restricted Subsidiaries acknowledge that, for
the convenience of all parties, this Agreement is being entered into with the
Bank only and that, in the event the Bank sells one or more participation
interests in the Loans, the Borrower's and each of the Restricted Subsidiary's
obligations under this Agreement are undertaken for the benefit of, and as an
inducement to, each of the participating lenders as well as the Bank, and the
Borrower and each of the Restricted Subsidiaries hereby grants to each of the
participating lenders to the extent of its participation in any Loan the right
to set off deposit accounts maintained by the Borrower or the Restricted
Subsidiaries with the Bank or such participating lenders. The Borrower and the
Restricted


                                       26

<PAGE>

Subsidiaries understand that the terms of such participation agreements with any
of the participating lenders may limit the Bank's rights to amend, waive or
modify the terms and conditions of this Agreement without the express written
consent of all or a designated percentage of such participants.

     SECTION 8.14. COUNTERPARTS. This Agreement, and each of the Loan Documents,
may be executed in one or more counterparts, each of which shall be deemed to be
an original, but which together shall constitute one and the same instrument.
The signatures of all of the parties hereto need not appear on the same
counterpart, and delivery of an executed counterpart signature page by facsimile
is as effective as executing and delivering this Agreement, and each of the Loan
Documents, in the presence of the other parties to this Agreement. Any party
delivering an executed counterpart of this Agreement or any of the Loan
Documents by facsimile shall also deliver a manually executed counterpart of
this Agreement and such Loan Documents, but the failure to do so shall not
affect the validity, enforceability or binding effect of this Agreement or such
Loan Documents.

     SECTION 8.15. CREDIT AGREEMENT. A CREDIT AGREEMENT MUST BE IN WRITING TO BE
ENFORCEABLE UNDER NEBRASKA LAW. TO PROTECT THE PARTIES HERETO FROM ANY
MISUNDERSTANDING OR DISAPPOINTMENTS, ANY CONTRACT, PROMISE, UNDERTAKING, OR
OFFER TO FORBEAR REPAYMENT OF MONEY OR TO MAKE ANY OTHER FINANCIAL ACCOMMODATION
IN CONNECTION WITH THIS LOAN OF MONEY OR GRANT OR EXTENSION OF CREDIT, OR ANY
AMENDMENT OF, CANCELLATION OF, WAIVER OF, OR SUBSTITUTION FOR ANY OR ALL OF THE
TERMS OR PROVISIONS OF ANY INSTRUMENT OR DOCUMENT EXECUTED IN CONNECTION WITH
THIS LOAN OF MONEY OR GRANT OR EXTENSION OF CREDIT, MUST BE IN WRITING TO BE
EFFECTIVE.

                      REMAINDER OF PAGE INTENTIONALLY BLANK


                                       27

<PAGE>

     IN WITNESS WHEREOF, the parties have caused this Agreement to be executed
by their respective officers thereunto duly authorized, as of the date first
above written.

                                        "Borrower"

                                        VERASUN ENERGY CORPORATION,
                                        a South Dakota corporation


                                        By: /s/ Donald L. Endres
                                            ------------------------------------
                                        Title: Chief Executive Officer
                                               ---------------------------------

                                        "Bank"


                                        First National Bank of Omaha,
                                        a national banking association


                                        By: /s/ Natalie E. Mason
                                            ------------------------------------
                                        Title: Commercial Loan Officer


                                        VERASUN AURORA CORPORATION,
                                        a South Dakota corporation


                                        By: /s/ Bruce A. Jamerson
                                            ------------------------------------
                                        Title: President and Chief Financial
                                               Officer
                                               ---------------------------------


                                        VERASUN FORT DODGE, LLC,
                                        a Delaware limited liability company


                                        By: /s/ Bruce A. Jamerson
                                            ------------------------------------
                                        Title: President and Chief Financial
                                               Officer
                                               ---------------------------------


                                        VERASUN CHARLES CITY, LLC
                                        a Delaware limited liability company


                                        By: /s/ Bruce A. Jamerson
                                            ------------------------------------
                                        Title: President and Chief Financial
                                               Officer
                                               ---------------------------------


                                       28

<PAGE>

                                  EXHIBIT LIST

EXHIBIT "A" BORROWING BASE CERTIFICATE
EXHIBIT "B" COMMITMENT LETTER
EXHIBIT "C" BORROWER CONTROL AGREEMENT
EXHIBIT "D" AURORA CONTROL AGREEMENT
EXHIBIT "E" CHARLES CITY CONTROL AGREEMENT
EXHIBIT "F" FORT DODGE CONTROL AGREEMENT
EXHIBIT "G" OPERATING NOTE
EXHIBIT "H" SECURITY AGREEMENT
EXHIBIT "I" AURORA SUBSIDIARY GUARANTY
EXHIBIT "J" CHARLES CITY SUBSIDIARY GUARANTY
EXHIBIT "K" FORT DODGE SUBSIDIARY GUARANTY
EXHIBIT "L" AURORA SUBSIDIARY SECURITY AGREEMENT
EXHIBIT "M" CHARLES CITY SUBSIDIARY SECURITY AGREEMENT
EXHIBIT "N" FORT DODGE SUBSIDIARY SECURITY AGREEMENT
EXHIBIT "O" OPINION LETTER BORROWER'S CORPORATE COUNSEL
EXHIBIT "P" OPINION LETTER BORROWER'S
            SOUTH DAKOTA AND NEBRASKA COUNSEL
EXHIBIT "Q" INTENTIONALLY OMITTED
EXHIBIT "R" INTENTIONALLY OMITTED
EXHIBIT "S" SUBSIDIARIES
EXHIBIT "T" FORM OF QUARTERLY PRODUCTION REPORT


                                       29

<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "A"

                           BORROWING BASE CERTIFICATE

                                 [See Attached]


<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "B"

                                COMMITMENT LETTER

                                 [See Attached]


<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "C"

                           BORROWER CONTROL AGREEMENT

                                 [See Attached]


<PAGE>
                                                                       EXHIBIT C

                                CONTROL AGREEMENT
               REGARDING SECURITY INTEREST IN INVESTMENT PROPERTY

     This CONTROL AGREEMENT (this "Agreement"), made as of the 21st day of
December, 2005, by and among First National Bank of Omaha, a national banking
association with its principal offices in Omaha, Nebraska ("BANK"), and VeraSun
Energy Corporation, a South Dakota corporation whose mailing address is 100 22nd
Avenue, Brookings, South Dakota 57006 (the "CUSTOMER"), and First National
Capital Markets, Inc., a Nebraska corporation whose mailing address is 1620
Dodge St., Omaha, Nebraska 68197 (the "COMPANY").

                                    RECITALS

     A. CUSTOMER is indebted to BANK as the result of one or more promissory
notes, or other evidence of indebtedness. Such indebtedness, whether resulting
from a promissory note, guaranty, letter of credit, or any other document or
cause, is herein called an "OBLIGATION."

     B. For purposes of this Agreement, all capitalized terms not otherwise
defined herein have the same meanings as defined in the Nebraska Uniform
Commercial Code (the "UCC").

     C. CUSTOMER has provided BANK a security interest in the COLLATERAL (as
defined below) and CUSTOMER desires to provide BANK with CONTROL (as such term
is defined in Nebraska Uniform Commercial Code Section 8-106) over the
COLLATERAL (as defined below).

     Now, therefore, the parties hereto agree as follows:

     1. The COMPANY represents and agrees that: (i) it has established and is
maintaining on its books and records the Securities Account, accounts number #
229000136 and 232000011, (said accounts, together with any replacements thereof
or substitutions therefore, is herein the "ACCOUNT") and (ii) the ACCOUNT is a
"securities account" (within the meaning of Section 8-501(a) of the UCC) in
respect of which the COMPANY is a "securities intermediary" (within the meaning
of Section 8-102(a)(14) of the UCC) and the BANK is the "entitlement holder"
(within the meaning of Section 8-102(a)(7) of the UCC).

     2. The COMPANY hereby agrees that each item of property (whether cash, a
security, an instrument or any other property whatsoever) credited to the
ACCOUNT shall be treated as FINANCIAL ASSETS under Article 8 of the UCC (the
ACCOUNT and the FINANCIAL ASSETS credited thereto shall be hereafter referred to
as the "COLLATERAL").

     3. The COMPANY agrees that, if there is any conflict between this Agreement
and any other agreement relating to the ACCOUNT, the provisions of this
Agreement shall control.

     4. COMPANY agrees that it will comply with INSTRUCTIONS and ENTITLEMENT
ORDERS originated by BANK as to the COLLATERAL, without further consent of
CUSTOMER. Until otherwise instructed, CUSTOMER is to receive any cash dividends
attributable to the COLLATERAL.

<PAGE>

     5. Notwithstanding the provisions of paragraph 4, above, CUSTOMER
possesses, along with the BANK, the right to originate INSTRUCTIONS to COMPANY
as to substitutions for the COLLATERAL, until BANK provides written notice to
COMPANY of any default (which is not cured or waived) by CUSTOMER as to any
OBLIGATION, thereafter BANK alone shall have the right to originate INSTRUCTIONS
to COMPANY as to the COLLATERAL. After COMPANY receives notice from BANK that a
default has occurred, COMPANY agrees that it will no longer comply with
ENTITLEMENT ORDERS originated by, or other directions or INSTRUCTIONS received
from, CUSTOMER with respect to the ACCOUNT or cash, securities or other property
credited thereto.

     6. COMPANY hereby agrees that any security interest, pledge,
right-of-setoff, mortgage, or other instrument now or hereinafter evidencing or
securing any OBLIGATION owed by the CUSTOMER to COMPANY shall be subordinated at
all times to the security interest, pledge, mortgage, or other instrument
securing the OBLIGATIONS owed to BANK whether now existing or hereinafter
arising (the "Subordinated Interest"). COMPANY shall not demand, accept or
receive any payment by CUSTOMER for or on account of the Subordinated Interest,
other than customary account or transaction fees incurred in the ordinary course
of business, without BANK's prior written consent. If COMPANY receives any
payment or COLLATERAL from CUSTOMER in violation of this Agreement, then COMPANY
shall hold the same in trust for BANK's benefit and forthwith deliver the same
to BANK in the form received duly endorsed in any manner BANK may determine in
its sole discretion. The Subordinated Interest of COMPANY shall continue until
such time as all of the OBLIGATIONS owed to the BANK are paid in full

     7. This Agreement is deemed to have been executed in Nebraska and any and
all matters arising under or related to this Agreement are and shall be governed
by and subject to the laws of Nebraska, including the UCC. This Agreement is
effective until terminated by a written notice executed by BANK delivered to
COMPANY, or until the COLLATERAL is no longer registered to or owned by
CUSTOMER.

     8. COMPANY represents that it has not and covenants that it will not agree
to comply with any INSTRUCTIONS or ENTITLEMENT ORDERS with respect to the
COLLATERAL other than as set forth herein.

                      REMAINDER OF PAGE INTENTIONALLY BLANK


                                   Page 2 of 3

<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first set forth above.

BANK:

First National Bank of Omaha,
a national banking association


By:
    ---------------------------------
    Natalie E. Mason,
    Commercial Loan Officer


CUSTOMER:

VeraSun Energy Corporation,
a South Dakota corporation


By:
    ---------------------------------
Name:
      -------------------------------
Title:
       ------------------------------


COMPANY:

First National Capital Markets, Inc.,
a Nebraska corporation


By:
    ---------------------------------
Name:
      -------------------------------
Title:
       ------------------------------


                                   Page 3 of 3
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "D"

                            AURORA CONTROL AGREEMENT

                                 [See Attached]


<PAGE>
                                                                       EXHIBIT D

                                CONTROL AGREEMENT
               REGARDING SECURITY INTEREST IN INVESTMENT PROPERTY

     This CONTROL AGREEMENT (this "Agreement"), made as of the 21st day of
December, 2005, by and among First National Bank of Omaha, a national banking
association with its principal offices in Omaha, Nebraska ("BANK"), and VeraSun
Aurora Corporation, a South Dakota corporation whose mailing address is 100 22nd
Avenue, Brookings, South Dakota 57006 (the "CUSTOMER"), and First National
Capital Markets, Inc., a Nebraska corporation whose mailing address is 1620
Dodge St., Omaha, Nebraska 68197 (the "COMPANY").

                                    RECITALS

     A. CUSTOMER has undertaken certain obligations to BANK as the result of one
or more guaranties, security agreements, letters of credit or other evidence of
indebtedness. Such indebtedness, whether resulting from such guaranties,
security agreements, letters of credit, or any other document or cause, is
herein called an "OBLIGATION."

     B. For purposes of this Agreement, all capitalized terms not otherwise
defined herein have the same meanings as defined in the Nebraska Uniform
Commercial Code (the "UCC").

     C. CUSTOMER has provided BANK a security interest in the COLLATERAL (as
defined below) and CUSTOMER desires to provide BANK with CONTROL (as such term
is defined in Nebraska Uniform Commercial Code Section 8-106) over the
COLLATERAL (as defined below).

     Now, therefore, the parties hereto agree as follows:

     1. The COMPANY represents and agrees that: (i) it has established and is
maintaining on its books and records the Securities Account, account number #
186000344, (said account, together with any replacements thereof or
substitutions therefore, is herein the "ACCOUNT") and (ii) the ACCOUNT is a
"securities account" (within the meaning of Section 8-501(a) of the UCC) in
respect of which the COMPANY is a "securities intermediary" (within the meaning
of Section 8-102(a)(14) of the UCC) and the BANK is the "entitlement holder"
(within the meaning of Section 8-102(a)(7) of the UCC).

     2. The COMPANY hereby agrees that each item of property (whether cash, a
security, an instrument or any other property whatsoever) credited to the
ACCOUNT shall be treated as FINANCIAL ASSETS under Article 8 of the UCC (the
ACCOUNT and the FINANCIAL ASSETS credited thereto shall be hereafter referred to
as the "COLLATERAL").

     3. The COMPANY agrees that, if there is any conflict between this Agreement
and any other agreement relating to the ACCOUNT, the provisions of this
Agreement shall control.

     4. COMPANY agrees that it will comply with INSTRUCTIONS and ENTITLEMENT
ORDERS originated by BANK as to the COLLATERAL, without further

<PAGE>

consent of CUSTOMER. Until otherwise instructed, CUSTOMER is to receive any cash
dividends attributable to the COLLATERAL.

     5. Notwithstanding the provisions of paragraph 4, above, CUSTOMER
possesses, along with the BANK, the right to originate INSTRUCTIONS to COMPANY
as to substitutions for the COLLATERAL, until BANK provides written notice to
COMPANY of any default (which is not cured or waived) by CUSTOMER as to any
OBLIGATION, thereafter BANK alone shall have the right to originate INSTRUCTIONS
to COMPANY as to the COLLATERAL. After COMPANY receives notice from BANK that a
default has occurred, COMPANY agrees that it will no longer comply with
ENTITLEMENT ORDERS originated by, or other directions or INSTRUCTIONS received
from, CUSTOMER with respect to the ACCOUNT or cash, securities or other property
credited thereto.

     6. COMPANY hereby agrees that any security interest, pledge,
right-of-setoff, mortgage, or other instrument now or hereinafter evidencing or
securing any OBLIGATION owed by the CUSTOMER to COMPANY shall be subordinated at
all times to the security interest, pledge, mortgage, or other instrument
securing the OBLIGATIONS owed to BANK whether now existing or hereinafter
arising (the "Subordinated Interest"). COMPANY shall not demand, accept or
receive any payment by CUSTOMER for or on account of the Subordinated Interest,
other than customary account or transaction fees incurred in the ordinary course
of business, without BANK's prior written consent. If COMPANY receives any
payment or COLLATERAL from CUSTOMER in violation of this Agreement, then COMPANY
shall hold the same in trust for BANK's benefit and forthwith deliver the same
to BANK in the form received duly endorsed in any manner BANK may determine in
its sole discretion. The Subordinated Interest of COMPANY shall continue until
such time as all of the OBLIGATIONS owed to the BANK are paid in full

     7. This Agreement is deemed to have been executed in Nebraska and any and
all matters arising under or related to this Agreement are and shall be governed
by and subject to the laws of Nebraska, including the UCC. This Agreement is
effective until terminated by a written notice executed by BANK delivered to
COMPANY, or until the COLLATERAL is no longer registered to or owned by
CUSTOMER.

     8. COMPANY represents that it has not and covenants that it will not agree
to comply with any INSTRUCTIONS or ENTITLEMENT ORDERS with respect to the
COLLATERAL other than as set forth herein.

                      REMAINDER OF PAGE INTENTIONALLY BLANK


                                   Page 2 of 3

<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first set forth above.

BANK:

First National Bank of Omaha,
a national banking association


By:
    ---------------------------------
    Natalie E. Mason,
    Commercial Loan Officer


CUSTOMER:

VeraSun Aurora Corporation,
a South Dakota corporation


By:
    ---------------------------------
Name:
      -------------------------------
Title:
       ------------------------------


COMPANY:

First National Capital Markets, Inc.,
a Nebraska corporation


By:
    ---------------------------------
Name:
      -------------------------------
Title:
       ------------------------------


                                   Page 3 of 3
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "E"

                         CHARLES CITY CONTROL AGREEMENT

                                 [See Attached]



<PAGE>
                                                                       EXHIBIT E

                                CONTROL AGREEMENT
               REGARDING SECURITY INTEREST IN INVESTMENT PROPERTY

     This CONTROL AGREEMENT (this "Agreement"), made as of the 21st day of
December, 2005, by and among First National Bank of Omaha, a national banking
association with its principal offices in Omaha, Nebraska ("BANK"), and VeraSun
Charles City, LLC, a Delaware limited liability company whose mailing address is
100 22nd Avenue, Brookings, South Dakota 57006 (the "CUSTOMER"), and First
National Capital Markets, Inc., a Nebraska corporation whose mailing address is
1620 Dodge St., Omaha, Nebraska 68197 (the "COMPANY").

                                    RECITALS

     A. CUSTOMER has undertaken certain obligations to BANK as the result of one
or more guaranties, security agreements, letters of credit or other evidence of
indebtedness. Such indebtedness, whether resulting from such guaranties,
security agreements, letters of credit, or any other document or cause, is
herein called an "OBLIGATION."

     B. For purposes of this Agreement, all capitalized terms not otherwise
defined herein have the same meanings as defined in the Nebraska Uniform
Commercial Code (the "UCC").

     C. CUSTOMER has provided BANK a security interest in the COLLATERAL (as
defined below) and CUSTOMER desires to provide BANK with CONTROL (as such term
is defined in Nebraska Uniform Commercial Code Section 8-106) over the
COLLATERAL (as defined below).

     Now, therefore, the parties hereto agree as follows:

     1. The COMPANY represents and agrees that: (i) it has established and is
maintaining on its books and records the Securities Account, account number (#
to be established as required and subject hereto), (said account, together with
any replacements thereof or substitutions therefore, is herein the "ACCOUNT")
and (ii) the ACCOUNT is a "securities account" (within the meaning of Section
8-501(a) of the UCC) in respect of which the COMPANY is a "securities
intermediary" (within the meaning of Section 8-102(a)(14) of the UCC) and the
BANK is the "entitlement holder" (within the meaning of Section 8-102(a)(7) of
the UCC).

     2. The COMPANY hereby agrees that each item of property (whether cash, a
security, an instrument or any other property whatsoever) credited to the
ACCOUNT shall be treated as FINANCIAL ASSETS under Article 8 of the UCC (the
ACCOUNT and the FINANCIAL ASSETS credited thereto shall be hereafter referred to
as the "COLLATERAL").

     3. The COMPANY agrees that, if there is any conflict between this Agreement
and any other agreement relating to the ACCOUNT, the provisions of this
Agreement shall control.

<PAGE>

     4. COMPANY agrees that it will comply with INSTRUCTIONS and ENTITLEMENT
ORDERS originated by BANK as to the COLLATERAL, without further consent of
CUSTOMER. Until otherwise instructed, CUSTOMER is to receive any cash dividends
attributable to the COLLATERAL.

     5. Notwithstanding the provisions of paragraph 4, above, CUSTOMER
possesses, along with the BANK, the right to originate INSTRUCTIONS to COMPANY
as to substitutions for the COLLATERAL, until BANK provides written notice to
COMPANY of any default (which is not cured or waived) by CUSTOMER as to any
OBLIGATION, thereafter BANK alone shall have the right to originate INSTRUCTIONS
to COMPANY as to the COLLATERAL. After COMPANY receives notice from BANK that a
default has occurred, COMPANY agrees that it will no longer comply with
ENTITLEMENT ORDERS originated by, or other directions or INSTRUCTIONS received
from, CUSTOMER with respect to the ACCOUNT or cash, securities or other property
credited thereto.

     6. COMPANY hereby agrees that any security interest, pledge,
right-of-setoff, mortgage, or other instrument now or hereinafter evidencing or
securing any OBLIGATION owed by the CUSTOMER to COMPANY shall be subordinated at
all times to the security interest, pledge, mortgage, or other instrument
securing the OBLIGATIONS owed to BANK whether now existing or hereinafter
arising (the "Subordinated Interest"). COMPANY shall not demand, accept or
receive any payment by CUSTOMER for or on account of the Subordinated Interest,
other than customary account or transaction fees incurred in the ordinary course
of business, without BANK's prior written consent. If COMPANY receives any
payment or COLLATERAL from CUSTOMER in violation of this Agreement, then COMPANY
shall hold the same in trust for BANK's benefit and forthwith deliver the same
to BANK in the form received duly endorsed in any manner BANK may determine in
its sole discretion. The Subordinated Interest of COMPANY shall continue until
such time as all of the OBLIGATIONS owed to the BANK are paid in full

     7. This Agreement is deemed to have been executed in Nebraska and any and
all matters arising under or related to this Agreement are and shall be governed
by and subject to the laws of Nebraska, including the UCC. This Agreement is
effective until terminated by a written notice executed by BANK delivered to
COMPANY, or until the COLLATERAL is no longer registered to or owned by
CUSTOMER.

     8. COMPANY represents that it has not and covenants that it will not agree
to comply with any INSTRUCTIONS or ENTITLEMENT ORDERS with respect to the
COLLATERAL other than as set forth herein.

                      REMAINDER OF PAGE INTENTIONALLY BLANK


                                  Page 2 of 3

<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first set forth above.

BANK:

First National Bank of Omaha,
a national banking association


By:
    ---------------------------------
    Natalie E. Mason,
    Commercial Loan Officer


CUSTOMER:

VeraSun Charles City, LLC,
a Delaware limited liability company


By:
    ---------------------------------
Name:
      -------------------------------
Title:
       ------------------------------


COMPANY:

First National Capital Markets, Inc.,
a Nebraska corporation


By:
    ---------------------------------
Name:
      -------------------------------
Title:
       ------------------------------


                                  Page 3 of 3
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "F"

                          FORT DODGE CONTROL AGREEMENT

                                 [See Attached]


<PAGE>
                                                                       EXHIBIT F

                                CONTROL AGREEMENT
               REGARDING SECURITY INTEREST IN INVESTMENT PROPERTY

     This CONTROL AGREEMENT (this "Agreement"), made as of the 21st day of
December, 2005, by and among First National Bank of Omaha, a national banking
association with its principal offices in Omaha, Nebraska ("BANK"), and VeraSun
Fort Dodge, LLC, a Delaware limited liability company whose mailing address is
100 22nd Avenue, Brookings, South Dakota 57006 (the "CUSTOMER"), and First
National Capital Markets, Inc., a Nebraska corporation whose mailing address is
1620 Dodge St., Omaha, Nebraska 68197 (the "COMPANY").

                                    RECITALS

     A. CUSTOMER has undertaken certain obligations to BANK as the result of one
or more guaranties, security agreements, letters of credit or other evidence of
indebtedness. Such indebtedness, whether resulting from such guaranties,
security agreements, letters of credit, or any other document or cause, is
herein called an "OBLIGATION."

     B. For purposes of this Agreement, all capitalized terms not otherwise
defined herein have the same meanings as defined in the Nebraska Uniform
Commercial Code (the "UCC").

     C. CUSTOMER has provided BANK a security interest in the COLLATERAL (as
defined below) and CUSTOMER desires to provide BANK with CONTROL (as such term
is defined in Nebraska Uniform Commercial Code Section 8-106) over the
COLLATERAL (as defined below).

     Now, therefore, the parties hereto agree as follows:

     1. The COMPANY represents and agrees that: (i) it has established and is
maintaining on its books and records the Securities Account, accounts number #
229000032, 229000033 and 208000140, (said accounts, together with any
replacements thereof or substitutions therefore, is herein the "ACCOUNT") and
(ii) the ACCOUNT is a "securities account" (within the meaning of Section
8-501(a) of the UCC) in respect of which the COMPANY is a "securities
intermediary" (within the meaning of Section 8-102(a)(14) of the UCC) and the
BANK is the "entitlement holder" (within the meaning of Section 8-102(a)(7) of
the UCC).

     2. The COMPANY hereby agrees that each item of property (whether cash, a
security, an instrument or any other property whatsoever) credited to the
ACCOUNT shall be treated as FINANCIAL ASSETS under Article 8 of the UCC (the
ACCOUNT and the FINANCIAL ASSETS credited thereto shall be hereafter referred to
as the "COLLATERAL").

     3. The COMPANY agrees that, if there is any conflict between this Agreement
and any other agreement relating to the ACCOUNT, the provisions of this
Agreement shall control.

<PAGE>

     4. COMPANY agrees that it will comply with INSTRUCTIONS and ENTITLEMENT
ORDERS originated by BANK as to the COLLATERAL, without further consent of
CUSTOMER. Until otherwise instructed, CUSTOMER is to receive any cash dividends
attributable to the COLLATERAL.

     5. Notwithstanding the provisions of paragraph 4, above, CUSTOMER
possesses, along with the BANK, the right to originate INSTRUCTIONS to COMPANY
as to substitutions for the COLLATERAL, until BANK provides written notice to
COMPANY of any default (which is not cured or waived) by CUSTOMER as to any
OBLIGATION, thereafter BANK alone shall have the right to originate INSTRUCTIONS
to COMPANY as to the COLLATERAL. After COMPANY receives notice from BANK that a
default has occurred, COMPANY agrees that it will no longer comply with
ENTITLEMENT ORDERS originated by, or other directions or INSTRUCTIONS received
from, CUSTOMER with respect to the ACCOUNT or cash, securities or other property
credited thereto.

     6. COMPANY hereby agrees that any security interest, pledge,
right-of-setoff, mortgage, or other instrument now or hereinafter evidencing or
securing any OBLIGATION owed by the CUSTOMER to COMPANY shall be subordinated at
all times to the security interest, pledge, mortgage, or other instrument
securing the OBLIGATIONS owed to BANK whether now existing or hereinafter
arising (the "Subordinated Interest"). COMPANY shall not demand, accept or
receive any payment by CUSTOMER for or on account of the Subordinated Interest,
other than customary account or transaction fees incurred in the ordinary course
of business, without BANK's prior written consent. If COMPANY receives any
payment or COLLATERAL from CUSTOMER in violation of this Agreement, then COMPANY
shall hold the same in trust for BANK's benefit and forthwith deliver the same
to BANK in the form received duly endorsed in any manner BANK may determine in
its sole discretion. The Subordinated Interest of COMPANY shall continue until
such time as all of the OBLIGATIONS owed to the BANK are paid in full

     7. This Agreement is deemed to have been executed in Nebraska and any and
all matters arising under or related to this Agreement are and shall be governed
by and subject to the laws of Nebraska, including the UCC. This Agreement is
effective until terminated by a written notice executed by BANK delivered to
COMPANY, or until the COLLATERAL is no longer registered to or owned by
CUSTOMER.

     8. COMPANY represents that it has not and covenants that it will not agree
to comply with any INSTRUCTIONS or ENTITLEMENT ORDERS with respect to the
COLLATERAL other than as set forth herein.

                      REMAINDER OF PAGE INTENTIONALLY BLANK


                                   Page 2 of 3

<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first set forth above.

BANK:

First National Bank of Omaha,
a national banking association


By:
    ------------------------------------------
    Natalie E. Mason, Commercial Loan Officer


CUSTOMER:

VeraSun Fort Dodge, LLC,
a Delaware limited liability company


By:
    ------------------------------------------
Name:
      ----------------------------------------
Title:
       ---------------------------------------


COMPANY:

First National Capital Markets, Inc.,
a Nebraska corporation


By:
    ------------------------------------------
Name:
      ----------------------------------------
Title:
       ---------------------------------------


                                   Page 3 of 3
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "G"

                                 OPERATING NOTE

                                 [See Attached]


<PAGE>
                                                                       EXHIBIT G

                                 OPERATING NOTE

$30,000,000.00                                                 December 21, 2005
                                                                 Omaha, Nebraska

     1. BORROWER'S PROMISE TO PAY. FOR VALUE RECEIVED, the undersigned, VERASUN
ENERGY CORPORATION, a South Dakota corporation (the "Borrower"), HEREBY PROMISES
TO PAY to the order of FIRST NATIONAL BANK OF OMAHA, a national banking
association (the "Bank"), at its principal office located at 1620 Dodge Street,
STOP 1050, Omaha, Nebraska 68197, in lawful money of the United States and in
immediately available funds, the principal amount of Thirty Million and
No/100ths Dollars ($30,000,000.00) or so much thereof as may be advanced by the
Bank pursuant to the terms and provisions of the Credit Agreement, as
hereinafter defined, between the Borrower and the Bank (the "Principal Amount"),
plus accrued and unpaid Interest thereon at the rate or rates described below,
on December 31, 2008 (the "Maturity Date").

     2. INTEREST.

          (a) The Principal Amount and any other amounts due hereunder shall
bear interest ("Interest") (computed on the basis of a year of 360 days for the
actual number of days elapsed) from the date of this Operating Note at a rate
per annum equal to the three (3) month LIBOR Rate plus three hundred (300) basis
points prior to acceleration or maturity. Any amount of principal hereof which
is not paid when due, whether at stated maturity, by acceleration, or otherwise,
shall bear interest from the date when due until said principal amount is paid
in full, payable on demand, at a rate per annum equal at all times to the three
(3) month LIBOR Rate plus six hundred (600) basis points ("Default Rate of
Interest"). Any change in the interest rate resulting from a change in the LIBOR
Reserve Percentage shall be adjusted automatically in accordance with the terms
and provisions of this Operating Note.

          (b) Assuming that this Operating Note does not mature, by acceleration
or otherwise, the interest rate applicable to this Operating Note is subject to
the following adjustments based upon the Borrower's Working Capital as of the
last Eurodollar Business Day of the three (3) month period ending at the end of
each calendar quarter during the term of this Operating Note prior to the
Maturity Date, (each such three month period, an "Adjustment Period"):

                      REMAINDER OF PAGE INTENTIONALLY BLANK

<PAGE>

<TABLE>
<CAPTION>
     IF, AS OF THE LAST EURODOLLAR          THEN THE INTEREST RATE APPLICABLE
    BUSINESS DAY OF ANY ADJUSTMENT            TO THIS OPERATING NOTE FOR THE
PERIOD, BORROWER'S WORKING CAPITAL IS:   SUBSEQUENT ADJUSTMENT PERIOD SHALL BE:
--------------------------------------   --------------------------------------
<S>                                      <C>
(i) less than $30,000,000.00, but        equal to three month LIBOR plus 300
greater than or equal to                 basis points or 3.00%
$15,000,000.00

(ii) less than $40,000,000.00, but       equal to three month LIBOR plus 275
greater than or equal to                 basis points or 2.75%
$30,000,000.00

(iii) greater than or equal to           equal to one month LIBOR plus 250 basis
$40,000,000.00                           points or 2.50%
</TABLE>

The adjustment provided for above shall be made by the Bank on each Adjustment
Date based upon the consolidated financial statements of the Borrower provided
to the Bank in accordance with Section 5.09 of the Credit Agreement for the
immediately preceding calendar quarter, and shall be effective as of the first
day of the calendar quarter, including the Adjustment Date.

     3. PAYMENTS.

          (a) Time and Amounts of Payments. All accrued and unpaid Interest on
     the outstanding Principal Amount shall be due and payable quarterly on a
     calendar quarter basis on the last day of each calendar quarter, commencing
     December 31, 2005, and continuing thereafter through and including the
     calendar quarter in which the Maturity Date occurs, and on the Maturity
     Date. On the Maturity Date, the Principal Amount and all accrued and unpaid
     Interest shall be due and payable by the Borrower to the Bank;

          (b) Business Day. If any payment is to be made on a day other than a
     Business Day, the maturity thereof shall be extended to the next succeeding
     Business Day, and the Interest shall be payable thereon at the rate herein
     specified during such extension;

          (c) Principal Amount. The Principal Amount of the Operating Note, if
     not sooner paid or declared to be due and payable in accordance with the
     terms of the Credit Agreement or this Operating Note, together with all
     accrued and unpaid Interest, shall be due and payable to the Bank on the
     Maturity Date;

          (d) Other Charges. To the extent permitted by Governing Law (as
     hereinafter defined), Borrower agrees to pay promptly upon demand all out
     of pocket expenses, including reasonable attorneys' fees and expenses,
     actually incurred by Bank in attempting to collect any amounts under this
     Operating Note or in any manner related to the security provided for
     hereunder. All such expenses shall be and become part of the Principal
     Amount due hereunder.

     4. CREDIT AGREEMENT. This Operating Note is the Operating Note referred to
in the Revolving Credit Agreement of even date herewith, by and among the
Borrower, the Bank, Aurora, Fort Dodge and Charles City, the terms and
provisions of which are incorporated


                                        2

<PAGE>

herein by this reference (the "Credit Agreement"). Capitalized terms not
otherwise defined in this Operating Note which are defined in the Credit
Agreement shall have the meanings ascribed thereto in the Credit Agreement. In
the event of a conflict or inconsistency between the terms of this Operating
Note and the Credit Agreement, the terms and provisions of the Credit Agreement
shall govern. The Credit Agreement, among other things, contains (i) enumerated
Events of Default, (ii) provisions for acceleration of the maturity of this
Operating Note upon the happening of certain stated events, and (iii) provisions
for prepayments of the Principal Amount of this Operating Note prior to the
maturity of the Operating Note upon the terms and conditions specified in the
Credit Agreement.

     5. EVENTS OF DEFAULT; REMEDIES. The occurrence of any Event of Default
enumerated in the Credit Agreement or any of the other Loan Documents shall
constitute an Event of Default under this Operating Note. As provided in the
Credit Agreement, upon any such Event of Default, the Bank shall have any and
all remedies provided in the Credit Agreement or any of the other Loan
Documents, including but not limited to the right, but not the obligation, to
accelerate the due date of this Operating Note and declare all obligations set
forth herein immediately due and payable, and such other remedies as are
provided by law.

     6. WAIVER BY BORROWER. BORROWER HEREBY IRREVOCABLY WAIVES, TO THE FULLEST
EXTENT PERMITTED BY GOVERNING LAW, PRESENTMENT FOR PAYMENT, NOTICE OF
NONPAYMENT, NOTICE OF DISHONOR, PROTEST, NOTICE OF PROTEST, DEMAND, NOTICE OF
EVERY KIND IN CONNECTION HEREWITH AND DILIGENCE IN ENFORCING PAYMENT OR BRINGING
SUIT AGAINST ANY PARTY HERETO.

     7. ACKNOWLEDGEMENT OF RECEIPT OF COPY. Borrower acknowledges receipt of a
copy of this Operating Note.

     8. MODIFICATION OR WAIVER REQUISITES. No modification of this Operating
Note shall be effective unless in writing, signed by the Borrower and the Bank.
No waiver of any right or power of Bank hereunder shall be effective unless in
writing, signed by the Bank and delivered to Borrower. No prior or subsequent
verbal communications not reduced to writing, executed by the parties, and
declared to be an integral part hereof are or shall be binding upon Borrower or
the Bank.

     9. NON-WAIVER BY BANK. The Bank's failure to exercise any right or power
upon the occurrence of an Event of Default, or any delay by the Bank in
exercising any such right or power, shall not constitute a waiver of such right
or power, or of any other right or power in the event of any subsequent
occurrence of an Event of Default, whether of the same or different nature.

     10. SECURITY. The Obligations of the Borrower under this Operating Note are
secured by (i) a Security Agreement of even date herewith from the Borrower to
the Bank referred to in the Credit Agreement, reference to which is hereby made
for a description of the collateral provided for under the Security Agreement
and the rights of the Borrower and the Bank with respect to such collateral,
(ii) a Control Agreement of even date herewith made by the


                                        3

<PAGE>

Borrower to the Bank (the "Control Agreement"), reference to which is hereby
made for a description of the collateral provided for under the Control
Agreement and the rights of the Borrower and the Bank with respect to such
collateral, (iii) a Subsidiary Guaranty of even date herewith made by Aurora to
the Bank (the "Aurora Guaranty"), guaranteeing the Borrower's full and timely
performance of all of its covenants, undertakings and obligations under the
provisions of the Loan Documents and the other agreements described therein,
(iv) the Subsidiary Security Agreement of even date herewith made by Aurora to
the Bank (the "Aurora Security Agreement"), reference to which is hereby made
for a description of the collateral provided for under the Aurora Security
Agreement and the rights of Aurora and the Bank with respect to such collateral,
(v) a Control Agreement of even date herewith made by Aurora to the Bank (the
"Aurora Control Agreement"), reference to which is hereby made for a description
of the collateral provided for under the Aurora Control Agreement and the rights
of Aurora and the Bank with respect to such collateral, (vi) a Subsidiary
Guaranty of even date herewith made by Fort Dodge to the Bank (the "Fort Dodge
Guaranty"), guaranteeing the Borrower's full and timely performance of all of
its covenants, undertakings and obligations under the provisions of the Loan
Documents and the other agreements described therein, (vii) the Subsidiary
Security Agreement of even date herewith made by Fort Dodge to the Bank (the
"Fort Dodge Security Agreement"), reference to which is hereby made for a
description of the collateral provided for under the Fort Dodge Security
Agreement and the rights of Fort Dodge and the Bank with respect to such
collateral, (viii) a Control Agreement of even date herewith made by Fort Dodge
to the Bank (the "Fort Dodge Control Agreement"), reference to which is hereby
made for a description of the collateral provided for under the Fort Dodge
Control Agreement and the rights of Fort Dodge and the Bank with respect to such
collateral, (ix) a Subsidiary Guaranty of even date herewith made by Charles
City to the Bank (the "Charles City Guaranty"), guaranteeing the Borrower's full
and timely performance of all of its covenants, undertakings and obligations
under the provisions of the Loan Documents and the other agreements described
therein, (x) the Subsidiary Security Agreement of even date herewith made by
Charles City to the Bank (the "Charles City Security Agreement"), reference to
which is hereby made for a description of the collateral provided for under the
Charles City Security Agreement and the rights of Charles City and the Bank with
respect to such collateral, (xi) a Control Agreement of even date herewith made
by Charles City to the Bank (the "Charles City Control Agreement"), reference to
which is hereby made for a description of the collateral provided for under the
Charles City Control Agreement and the rights of Charles City and the Bank with
respect to such collateral, and (xii) such other similar types of documents and
security described and referred to in the Credit Agreement, whether or not
executed and delivered on the date hereof or to be executed and delivered in the
future in accordance with the terms and provisions of the Credit Agreement.

     11. GOVERNING LAW. This Operating Note is made under and governed by the
laws of, and shall be deemed to have been executed in, the State of Nebraska
without giving effect to choice of law principles (whether of the State of
Nebraska or any other jurisdiction) that would cause the application of the laws
of any jurisdiction other than the State of Nebraska (the "Governing Law").

     12. COMMERCIAL NATURE OF LOAN. Borrower acknowledges that the Obligations
evidenced by this Operating Note are for business purposes only and are not an
extension of consumer or individual credit.


                                        4

<PAGE>

     13. PROHIBITION AGAINST USURY. In no event, either before or after the
occurrence of an Event of Default, shall the Interest due under this Operating
Note exceed the maximum, lawful, non-usurious interest rate of the State of
Nebraska or any other applicable law (the "Maximum Rate"). This Operating Note
is hereby expressly limited so that in no event whatsoever, whether by reason of
acceleration or otherwise, shall the amount paid, or agreed to be paid to Bank
for the use, forbearance or detention of the sums advanced to Borrower exceed
the Maximum Rate. If fulfillment of any provisions hereof, at the time
performance of such provision shall be due, shall involve the potential for
transcending the Maximum Rate, the obligation to be fulfilled shall be reduced
to the Maximum Rate, and if from any such circumstance the Bank shall ever
receive as Interest an amount which would exceed the Maximum Rate, such excess
shall be applied to the reduction of the Principal Amount and not the payment of
Interest, or if such excessive Interest exceeds the unpaid balance of the
Principal Amount, such excess shall be refunded to Borrower. All sums paid and
agreed to be paid to the Bank for use, forbearance or detention of the
indebtedness of Borrower shall, to the extent permitted by Governing Law, be
amortized, prorated, allocated, and spread through the whole term of such
indebtedness so that the actual rate of Interest on account of such indebtedness
is uniform throughout the term thereof.

     14. ASSIGNMENT. This Operating Note may be assigned, in whole or in part,
by the Bank, and Borrower agrees not to assert against any such assignee or
assignee's assigns, any defense, set-off, recoupment claim or counterclaim which
Borrower has or may at any time have against the Bank for any reason whatsoever,
except for payment of the Obligations. Borrower agrees that if Borrower receives
written notice of an assignment from the Bank, Borrower will pay all amounts
payable under this Operating Note to such assignee or as instructed by the Bank.
Borrower also agrees to confirm in writing receipt of the notice of assignment
as may be reasonably requested by the Bank or assignee. The Borrower may not
assign any of its rights or obligations hereunder without the prior written
consent of the Bank, which may be withheld in its sole discretion.

     15. SEVERABILITY. In the event any one or more of the provisions contained
in this Operating Note shall for any reason be held to be invalid, illegal or
unenforceable in any respect under Governing Law, such invalidity, illegality or
unenforceability, at the option of the Bank, shall not affect any other
provision of this Operating Note, but this Operating Note shall be construed as
if such invalid, illegal or unenforceable provision had never been contained
herein.

     16. SUBMISSION TO JURISDICTION; VENUE. To induce the Bank to enter into
this Operating Note, the Borrower irrevocably agrees that, subject to the Bank's
sole and absolute election, all suits, actions or other proceedings in any way,
manner or respect, arising out of or from or related to this Operating Note,
shall be subject to litigation in any state or federal court sitting in
Nebraska. The Borrower hereby consents and submits to the jurisdiction of any
local, state, or federal court located in Omaha, Nebraska. The Borrower hereby
waives any rights it may have to transfer or change the venue of any suit,
action or other proceeding brought against the Borrower by the Bank in
accordance with this Section 16 or in connection with this Operating Note.


                                        5

<PAGE>

     17. WAIVER OF JURY TRIAL. THE BANK AND THE BORROWER HEREBY WAIVE TRIAL BY
JURY IN ANY ACTION, PROCEEDING, CLAIM, OR COUNTERCLAIM, WHETHER IN CONTRACT OR
TORT, AT LAW OR IN EQUITY, ARISING OUT OF OR IN ANY WAY RELATED TO THIS
OPERATING NOTE. NO OFFICER OR EMPLOYEE OF THE BANK HAS AUTHORITY TO WAIVE,
CONDITION, OR MODIFY THIS PROVISION.

     18. CONSENT TO LOAN PARTICIPATION. Borrower agrees and consents to the
Bank's sale or transfer, at any time, of one or more participation interests in
this Operating Note, the Credit Agreement, the Loan Documents or any documents
referred to in the Credit Agreement to one or more purchasers (each a
"Participant"), whether related or unrelated to the Bank. The Bank may provide
to any Participant or any prospective Participant, any information or knowledge
the Bank may have regarding the Borrower or any matter relating to the subject
matter of the Credit Agreement, and the Borrower hereby waives any rights to
privacy it may have with respect to such matters. The Borrower additionally
waives any and all notices of sale of participation interests, as well as all
notices of any repurchase of such participation interests. Borrower also agrees
that any Participant will be considered as the absolute owner of such interest
in this Operating Note, the Credit Agreement, the Loan Documents or any
documents referred to in the Credit Agreement and will have all the rights
granted under the participation agreement(s) governing the sale of such
participation interest. The Borrower further waives all rights of offset or
counterclaim that it may now have or hereafter acquire against the Bank or any
Participant, and unconditionally agrees that either the Bank or any Participant
may enforce Borrower's obligation under this Operating Note, the Credit
Agreement, the Loan Documents or any documents referred to in the Credit
Agreement irrespective of the failure or insolvency of any holder of any
Participant interest. The Borrower further agrees that any Participant may
enforce its interests irrespective of any personal claims or defenses that
Borrower may have against the Bank.

     19. CREDIT AGREEMENT. A CREDIT AGREEMENT MUST BE IN WRITING TO BE
ENFORCEABLE UNDER NEBRASKA LAW. TO PROTECT THE PARTIES HERETO FROM ANY
MISUNDERSTANDING OR DISAPPOINTMENTS, ANY CONTRACT, PROMISE, UNDERTAKING, OR
OFFER TO FORBEAR REPAYMENT OF MONEY OR TO MAKE ANY OTHER FINANCIAL ACCOMMODATION
IN CONNECTION WITH THIS LOAN OF MONEY OR GRANT OR EXTENSION OF CREDIT, OR ANY
AMENDMENT OF, CANCELLATION OF, WAIVER OF, OR SUBSTITUTION FOR ANY OR ALL OF THE
TERMS OR PROVISIONS OF ANY INSTRUMENT OR DOCUMENT EXECUTED IN CONNECTION WITH
THIS LOAN OF MONEY OR GRANT OR EXTENSION OF CREDIT, MUST BE IN WRITING TO BE
EFFECTIVE.


                                        6

<PAGE>

     IN WITNESS WHEREOF, the Borrower has caused this Operating Note to be
executed and delivered to the Bank as of the day and year first written above.

                                        "Borrower"

                                        VERASUN ENERGY CORPORATION,
                                        a South Dakota corporation


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        7
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "H"

                               SECURITY AGREEMENT

                                 [See Attached]


<PAGE>
                                                                       EXHIBIT H

                               SECURITY AGREEMENT

     THIS SECURITY AGREEMENT (this "Agreement") is made as of the 21st day of
December, 2005, by VERASUN ENERGY CORPORATION, a South Dakota corporation
("Borrower"), whose mailing address is 100 22nd Avenue, Brookings, South Dakota
57006, in favor of FIRST NATIONAL BANK OF OMAHA, a national banking association
("Bank"), whose mailing address is 1620 Dodge Street, STOP 1050, Omaha, Nebraska
68197, its successors and assigns.

                                    RECITALS

     WHEREAS, Borrower and Bank have entered into a Revolving Credit Agreement
of even date herewith (as amended, restated, or otherwise modified from time to
time, the "Credit Agreement"), pursuant to which Borrower has undertaken certain
covenants and has executed and delivered to Bank an Operating Note of even date
herewith by the Borrower payable to the order of the Bank in the total principal
amount of Thirty Million Dollars ($30,000,000.00) the proceeds of which may be
drawn upon by the Borrower, for the purposes provided for in the Credit
Agreement, in accordance with and subject to the terms and restrictions
contained in the Credit Agreement (the "Note"); and

     WHEREAS, Bank has agreed to provide a Letter of Credit Facility, as
provided in the Credit Agreement, for the benefit of Borrower, whereby Bank, at
Borrower's request and subject to compliance with the terms and provisions of
the Credit Agreement, will issue one or more Letters of Credit in an aggregate
principal amount outstanding not to exceed Ten Million and No/100ths Dollars
($10,000,000.00), on behalf of Borrower or its Subsidiaries in accordance with
and subject to the terms and provisions of the Credit Agreement; and

     WHEREAS, Section 2.09 of the Credit Agreement provides that the purposes of
the Credit Agreement include providing the Borrower and the Subsidiaries with
access to (a) operating funds and (b) Letters of Credit for operating purposes;
and

     WHEREAS, Bank has, at the previous request of Borrower or certain
Restricted Subsidiaries, issued letters of credit for the benefit of certain
third-party creditors of the Borrower and certain Restricted Subsidiaries on or
prior to the date hereof (the "Prior Letters of Credit"); and

     WHEREAS, under the Credit Agreement, it is a condition precedent to (i)
Bank's making of Loans to the Borrower, and (ii) Bank's issuance of one or more
Letters of Credit on behalf of Borrower pursuant to the Credit Agreement, that
Borrower execute and deliver to Bank this Agreement; and

     WHEREAS, Borrower has agreed to grant a Security Interest (as hereinafter
defined) in the Collateral (as hereinafter defined) to Bank to secure the
Obligations (as hereinafter defined) in accordance with the terms and conditions
set forth herein.

<PAGE>

     NOW, THEREFORE, in consideration of the premises set forth above, and other
good and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, and intending to be legally bound, Borrower represents, warrants,
covenants, and agrees with Bank as follows:

     1. Definitions:

          (a) For purposes of this Agreement, "Receivables" shall mean any right
to payment for goods sold or leased or for services rendered, whether or not
such right is evidenced by an Instrument or Chattel Paper and whether or not it
has been earned by performance (including, without limitation, any Account).

          (b) All capitalized terms used in this Agreement, including its
preamble and recitals, and not otherwise defined herein, shall have the meaning
ascribed to them in the Credit Agreement.

          (c) Unless otherwise defined herein or in the Credit Agreement, or the
context otherwise requires, and whether or not capitalized, terms for which
meanings are provided in the Uniform Commercial Code, as in effect from time to
time in the State of Nebraska, are used in this Agreement with such meaning.

     2. Security Interest: Borrower hereby BARGAINS, SELLS, GRANTS, CONVEYS,
TRANSFERS, PLEDGES, HYPOTHECATES, and ASSIGNS to Bank a first priority security
interest (the "Security Interest") in any and all (a) Receivables, (b)
Inventory, (c) any cash Proceeds (including cash insurance proceeds thereof),
rents and profits of or in respect of any and all of the foregoing items listed
in 2 (a) or 2 (b) above, and (d) the Deposit Account and Securities Account
(including, but not limited to, Borrower's accounts # 110193438 and 110118219 at
the Bank, Borrower's accounts # 229000136 and 232000011 at First National
Capital Markets, Inc., and such Deposit Accounts and Securities Accounts the
Borrower may establish from time to time) into which the cash Proceeds of the
items listed in 2 (a), 2 (b) or 2 (c) above are deposited, owned by Borrower or
in which Borrower has an interest; together with all increases, replacements,
refurbishment, improvements, additions and substitutions therefor, all
after-acquired property with respect thereto, and all products, present and
future accessions and cash and noncash proceeds of the categories described
above, including contract rights, therefrom (collectively, the "Collateral"), to
secure the complete and timely payment, performance or discharge of (i) each of
the obligations and covenants of Borrower under this Agreement, the Credit
Agreement, the Note, the Control Agreement, the Letters of Credit, the Prior
Letters of Credit, and all modifications, substitutions, extensions and renewals
of each, whether absolute or contingent, liquidated or unliquidated, existing
now or arising in the future and (ii) all present and future indebtedness and
obligations of Borrower to Bank whether direct, indirect, absolute, or
contingent and whether arising by promissory note, letter of credit, guaranty,
overdraft, or otherwise (individually, an "Obligation" and collectively, the
"Obligations"). The Security Interest shall be effective with respect to each
item of Collateral for so long as any Obligation remains outstanding, regardless
of whether Borrower becomes the owner of such Collateral prior to or
contemporaneously with or subsequent to the incurring of such Obligation.

     3. Continued Attachment and Perfection: Further to insure the attachment,
perfection,


                                        2

<PAGE>

and first priority of, and the ability of Bank to enforce, the Security Interest
in the Collateral, Borrower agrees to take any other action reasonably requested
by Bank to insure the attachment, perfection and first priority of, and the
ability of Bank to enforce, the Security Interest in any and all of the
Collateral including, without limitation, (a) executing, delivering and, where
appropriate, filing financing statements and amendments relating thereto under
the Uniform Commercial Code, to the extent, if any, that the Borrower's
signature thereon is required therefor, (b) complying with any provision of any
statute, regulation, or treaty of the United States, or the law of the
jurisdiction in which the Collateral is located as to any Collateral if
compliance with such provision is a condition to attachment, perfection, or
priority of, or ability of Bank to enforce, the Security Interest in such
Collateral, (c) obtaining governmental and other third-party consents and
approvals, including without limitation any consent of any licensor, lessor, or
other Person obligated on the Collateral, and (d) taking all actions required by
any earlier versions of the Uniform Commercial Code or by any other law, as
applicable in any relevant Uniform Commercial Code jurisdiction, or by other law
as applicable in any foreign jurisdiction.

     4. Authorization to File Financing Statements: Borrower hereby irrevocably
authorizes Bank at any time and from time to time to file in any Uniform
Commercial Code jurisdiction any initial financing statements, amendments and
continuations thereto that contain any information required by Part 5 of Article
9 of the Uniform Commercial Code of such jurisdiction for the sufficiency or
filing office acceptance of any financing statement or amendment. The Borrower
agrees to furnish to Bank any information relating to the Collateral that Bank
may request.

     5. Representations and Warranties: Borrower expressly represents and
warrants to, and covenants with Bank that, for so long as the Security Interest
shall remain in effect:

          (a) Borrower has, or upon acquisition will have, and at all times
until disposed of in accordance with the terms hereof, will maintain, good and
marketable title to the Collateral, free and clear of any lien, pledge, security
interest, or other encumbrance except (i) the Security Interest, (ii) current
and non-delinquent taxes or taxes being contested as provided by applicable law
in good faith and by appropriate legal proceedings in a manner which, in
Borrower's reasonable judgment, will not jeopardize the Security Interest, and
(iii) liens arising in the ordinary course of business for sums not overdue or
sums being contested in good faith and by appropriate legal proceedings in a
manner which, in Borrower's reasonable judgment, will not jeopardize the
Security Interest, and Borrower will warrant and defend title to and possession
of the Collateral at Borrower's expense against all claims or demands of all
persons other than Bank.

          (b) No financing statement (or other notice of any lien, security
interest or encumbrance) covering any of the Collateral is on file with any
governmental official or authority, or has been or will be delivered by Borrower
to any person other than Bank without the prior written consent of Bank.

          (c) The execution and delivery of this Agreement shall not,
immediately or with the passage of time, the giving of notice, or otherwise,
constitute a breach of or default under any term or provision of, or trigger the
creation of a security interest in any of the Collateral (other than the
Security Interest provided herein) pursuant to, or accelerate the obligations of
Borrower under,


                                        3

<PAGE>

any contract, mortgage, deed of trust, indenture, letter of credit, lease,
license, permit, agreement or other instrument to which Borrower is or may
become a party or by which Borrower or the Collateral is or may be bound or
affected.

          (d) Along with this Agreement, Borrower is delivering to Bank a
certificate signed by Borrower and entitled "Perfection Certificate" and
attached hereto as Exhibit "A" and incorporated herein by reference (the
"Perfection Certificate"). Borrower represents and warrants to Bank as follows:
(i) Borrower's exact legal name is that indicated on the Perfection Certificate
and on the signature page hereof, (ii) Borrower is an organization of the type
and organized in the jurisdiction set forth in the Perfection Certificate, (iii)
the Perfection Certificate accurately sets forth Borrower's organizational
identification number or accurately states that Borrower has none, (iv) the
Perfection Certificate accurately sets forth Borrower's place of business or, if
more than one, its chief executive office as well as Borrower's mailing address,
if different, and (v) all other information set forth on the Perfection
Certificate pertaining to Borrower is accurate and complete.

          (e) Borrower covenants with Bank as follows: (i) without providing at
least thirty (30) days prior written notice to Bank, Borrower will not change
its name, its place of business or, if more than one, chief executive office, or
its mailing address or organizational identification number and (ii) Borrower
will not change its type of organization, jurisdiction of organization, or other
legal structure.

          (f) Borrower covenants with Bank that it will maintain with
financially sound and reputable insurers insurance with respect to its
properties, business and the Collateral against such casualties and
contingencies as shall be in accordance with general practices of businesses
engaged in similar activities in similar geographic areas and in accordance with
the Credit Agreement.

          (g) Borrower shall:

               (i) pay on a timely basis all taxes, assessments and other
federal, state or local governmental charges and penalties levied or assessed
upon or against any Collateral or upon or against the creation, perfection or
continuance of the Security Interest, provided that no such taxes, assessments,
charges or penalties need be paid if the same are being contested in good faith
by appropriate proceedings diligently instituted and conducted;

               (ii) promptly notify Bank of any material loss of or material
damage to any Collateral or any Event of Default (defined below) hereunder;

               (iii) not use or keep any Collateral, or permit it to be used or
kept, for any unlawful purpose or in violation of applicable law, or in such a
way as would limit or void any insurance maintained on any portion of the
Collateral;

               (iv) not conduct business under any name other than that given
herein, nor change or reorganize the type of entity under which it operates,
except upon written notice to the Bank within thirty (30) days prior to such
change;


                                        4

<PAGE>

               (v) not sell, assign, or transfer all or any part of the
Collateral to any Person for less than payment of full fair market value
therefor;

               (vi) perform and comply with all the terms and conditions of the
Note;

               (vii) perform and comply with all the terms and conditions of the
Credit Agreement;

               (viii) perform and comply with all the terms and conditions of
any Letter of Credit, including, but not limited to, the Prior Letters of
Credit, and each of the documents relating thereto;

               (ix) perform and comply with all the terms and conditions of the
Control Agreements to which it is a party;

               (x) do and perform all acts and things and execute all documents
which Bank in its reasonable discretion deems necessary or appropriate to
perfect, renew, or to give notice of, the Security Interest;

               (xi) notify Bank immediately of any legal process levied or filed
against any of the Collateral or Borrower or any other event which materially
and adversely affects or may materially and adversely affect the value, use or
possession of the Collateral or any of the rights of Borrower or Bank in
relation to any of the Collateral; and

               (xii) preserve in existence and in accordance with their
respective terms, all of its rights, franchises, licenses, material contracts,
permits and privileges necessary to its operation, and not dissolve, merge, or
consolidate into another entity or sell, lease, transfer, or otherwise dispose
of all or a substantial part of its assets, without the prior written consent of
Bank, which consent shall not be withheld unreasonably.

     6. Disposition of Collateral:  So long as there is no uncured or non-waived
Event of Default hereunder, Borrower may, in accordance with the other terms and
conditions  contained  herein,  sell or otherwise dispose of the Collateral when
obsolete,  worn out,  inadequate,  unserviceable  or unnecessary  for use in the
operation or conduct of  Borrower's  business,  upon (a)  replacing  the same or
substituting  for the same with other  Collateral at least equal in value to the
value  of  that  Collateral  disposed  of and in  such a  manner  so  that  such
replacement or substitution Collateral shall be subject to the Security Interest
and so that such Security Interest shall be first in priority, or (b) delivering
the proceeds from the  disposition of such Collateral to Bank for credit against
the  Obligations  or  deposit in an  account  which is  subject to the  Security
Interest.

     7. Miscellaneous Undertakings: Borrower, at its sole cost and expense,
agrees to:

          (a) pay all reasonable expenses, including without limitation,
reasonable attorneys' fees and court costs to the fullest extent permitted by
Governing Law (as hereinafter defined), actually incurred by Bank in connection
with the creation, perfection, preservation, or


                                        5

<PAGE>

enforcement of the Security Interest, the defense of the Collateral, or the
exercise by Bank of any of the rights, powers or remedies granted to Bank under
this Agreement, by law or otherwise; or

          (b) reimburse Bank within ten (10) days of Bank's demand for any
reasonable expense incurred by Bank pursuant to the foregoing authorization,
together with interest thereon at a rate equal to the lesser of (i) the three
(3) month LIBOR Rate, in effect from time to time, plus six hundred (600) basis
points, or (ii) the highest non-usurious rate of interest permitted by Governing
Law, from the date that any such expense is incurred, until reimbursed.

     8. Event of Default: The failure to cure a breach of or the failure to
comply with any material covenant, agreement, warranty, representation, or
undertaking of Borrower contained in this Agreement within ten (10) days of
receipt of notice thereof to Borrower from Bank shall, at the option of Bank and
without further notice or demand, constitute an "Event of Default" under this
Agreement. Additionally, the occurrence of a breach or non-fulfillment of the
terms and provisions of the Note, the Prior Letters of Credit, the Letters of
Credit, the Credit Agreement, or any of the other Loan Documents, if any such
breach or non-fulfillment is not cured in accordance with the respective terms
thereof, shall constitute an "Event of Default" under this Agreement. Further,
if for any reason the Security Interest granted hereby is not a first perfected
lien on the Collateral, or any portion thereof, it shall be deemed an "Event of
Default" under this Agreement.

     9. Bank's Rights Upon Event of Default: Upon the occurrence of an Event of
Default and at any time thereafter (unless cured or waived in each instance),
Bank may, to the fullest extent permitted by and with such notice as may be
required by Governing Law (Borrower hereby waiving any such required notice to
the fullest extent permitted by Governing Law):

          (a) enter upon any property upon which the Collateral is located and
take possession of, assemble, collect, and move any or all of the Collateral, or
render such Collateral unusable, and store any of the Collateral at locations
acceptable to Bank;

          (b) require Borrower to assemble any or all of the Collateral and make
it available at a mutually convenient place designated by Bank so as to permit
Bank to take possession of, move, or store, such Collateral;

          (c) sell, assign, or otherwise dispose of and deliver all or any part
of the Collateral at public or private sale, for cash or on credit, to a
wholesaler, retailer or user of each type of Collateral or at public auction;

          (d) bid and become purchaser at any public sale or auction of the
Collateral;

          (e) perform any of the Obligations, and apply any Collateral or the
proceeds therefrom to the payment of the Obligations in such order, priority and
manner as Bank in its sole discretion may determine;

          (f) operate, consume, sell or dispose of any of the Collateral as Bank
deems appropriate for the purpose of partially satisfying or fully satisfying
any or all of the Obligations;


                                        6

<PAGE>

          (g) transfer to itself or any nominee any securities constituting
Collateral, receive any income thereon and hold such income as additional
Collateral or apply it to the Obligations;

          (h) make any compromise or settlement which Bank may deem desirable or
proper with respect to any of the Collateral or any controversies or disputes
relating to the Collateral, and release any of the Collateral and any persons
liable on any of the Collateral;

          (i) endorse and deliver evidences of title, and receive, enforce and
collect by legal action or otherwise all or any portion of the Collateral; and

          (j) enforce, adjust and receive payment or performance in connection
with any insurance claims, claims for breach of warranty, claims under any
letters of credit, instruments, documents of title, chattel paper or contracts
and similar matters concerning any of the Collateral.

     10. No Responsibility: Borrower acknowledges that Bank has no
responsibility for, and does not assume any of, Borrower's obligations or duties
under any agreement, document of title, instrument, general intangible or other
contract or obligation relating to the Collateral. Bank shall have no duty or
obligation whatsoever to make or give any presentments, demands for performance,
notices of nonperformance, notices of protest or notices of dishonor in
connection with any of the Collateral or to take any other action to preserve,
protect or defend any of the Collateral or to preserve any value or utility of
any of the Collateral, except to the extent required by Governing Law (Borrower
hereby waiving any such required notices or actions to the fullest extent
permitted by Governing Law).

     11. No Waiver by Bank, Etc.: The Bank shall not be deemed to have waived
any of its rights upon or under the Obligations or the Collateral unless such
waiver shall be in writing and signed by the Bank. No delay or omission on the
part of the Bank in exercising any right shall operate as a waiver of such right
or any other right. A waiver on any one occasion shall not be construed as a bar
to or waiver of any right on any future occasion. All rights and remedies of the
Bank with respect to the Obligations or the Collateral, whether evidenced hereby
or by any other instrument or papers, shall be cumulative and may be exercised
singularly, alternatively, successively, or concurrently at such time or at such
times as the Bank deems expedient.

     12. Waivers by Borrower: To the fullest extent permitted under Governing
Law, the Borrower waives demand, notice, protest, notice of acceptance of this
Agreement, notice of Loans made, credit extended, Collateral received or
delivered, the issuance of one or more Letters of Credit or payments made
pursuant thereto or pursuant to the Prior Letters of Credit, or other action
taken in reliance hereon, and all other demands and notices of any description.
With respect to both the Obligations and the Collateral, the Borrower assents to
any extension or postponement of the time of payment or any other indulgence, to
any substitution, exchange, or release of or failure to perfect any security
interest in any Collateral, to the addition or release of any party or Person
primarily or secondarily liable, to the acceptance of partial payment thereon
and the settlement, compromising, or adjusting of any thereof, all in such
manner and at such time or times as the Bank may deem advisable. The Bank shall
have no duty as to the collection or protection of the Collateral or any


                                        7

<PAGE>

income thereon, nor as to the preservation of rights against prior parties, nor
as to the preservation of any rights pertaining thereto beyond the safe custody
thereof as set forth in Section 21. The Borrower further waives any and all
other suretyship defenses available under Governing Law.

     13. Notices: All notices and other communications provided for under this
Agreement shall be in writing (including facsimile transmissions) and mailed or
transmitted or delivered, if to the Borrower, at its address at 100 22nd Avenue,
Brookings, South Dakota 57006, Attention: Bruce Jamerson, and if to the Bank, at
its address at 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197, Attention:
Natalie E. Mason; or, as to each party, at such other address as shall be
designated by such party in a written notice to the other party complying as to
delivery with the terms of this Section 13. Except as otherwise provided in this
Agreement, all such notices and communications shall be effective when deposited
in the U.S. mail and addressed as aforesaid, except that notices to the Bank
pursuant to the provisions of this Section 13 shall not be effective until
received by the Bank.

     14. Successors and Assigns: The terms of this Agreement shall be binding
upon and inure to the benefit of the successors-in-interest and assigns of
Borrower and Bank; provided that Borrower may not assign its rights or
obligations under this Agreement by contract, operation of law, or otherwise
without the prior written consent of Bank, which may be withheld in Bank's sole
discretion.

     15. Time is of the Essence: Time is an essential element to the performance
of each term of this Agreement.

     16. Headings: All headings appearing in this Agreement are for convenience
of reference only and shall be disregarded in construing this Agreement.

     17. Governing Law: This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Nebraska without giving effect to any
choice or conflict of law provision or rule (whether of the State of Nebraska or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Nebraska (the "Governing Law").

     18. Miscellaneous: The rights and remedies of Bank under this Agreement are
cumulative, and no exercise of any right or remedy shall preclude the exercise
of any other right or remedy or the later exercise of the same right or remedy.
Waivers and approvals under this Agreement shall be in writing and unless
otherwise expressly stated, waivers and approvals shall apply only to the
specific circumstance addressed. Notwithstanding any other provision of this
Agreement, Bank shall not be deemed to have accepted any property other than
cash in satisfaction of any Obligation unless Bank shall make an express written
election of said remedy under Governing Law.

     19. Amendment: This Agreement shall not be amended or modified in any way
except by a written instrument executed by Bank and Borrower.


                                        8

<PAGE>

     20. Severability: In the event any one or more of the provisions contained
in this Agreement shall for any reason be held to be invalid, illegal or
unenforceable in any respect under Governing Law, such invalidity, illegality or
unenforceability, at the option of Bank, shall not affect any other provision of
this Agreement, but this Agreement shall be construed as if such invalid,
illegal or unenforceable provision had never been contained herein. If the
Security Interest is invalid or unenforceable as to any portion of the
Obligations or the Collateral, all payments made on the Obligations, whether
voluntary or under foreclosure or other enforcement action or procedure, shall
be applied first to the full payment of that portion of the Obligations not
secured or not fully secured by the Collateral.

     21. Bank's Duty of Care: Bank's duty of care with respect to Collateral in
its possession shall be deemed fulfilled if Bank exercises ordinary care in
physically safekeeping and preserving such Collateral or, in the case of
Collateral in the custody or possession of a bailee or other third person, Bank
exercises ordinary care in the selection of the bailee or other third person.

     22. Preservation of Rights: Bank shall not be obligated to preserve any
rights Borrower may have against other parties, to realize on the Collateral at
all or in any particular manner or order, or to apply any cash proceeds of
Collateral in any particular order of application, except as otherwise expressly
provided herein.

     23. Jury Trial Waiver: THE BORROWER HEREBY WAIVES TRIAL BY JURY IN ANY
ACTION, PROCEEDING, CLAIM, OR COUNTERCLAIM, WHETHER IN CONTRACT OR TORT, AT LAW
OR IN EQUITY, ARISING OUT OF OR IN ANY WAY RELATED TO THIS AGREEMENT. NO
EMPLOYEE OF THE BANK HAS AUTHORITY TO WAIVE, CONDITION, OR MODIFY THE TERMS AND
PROVISIONS OF THIS SECTION OF THIS AGREEMENT.

     24. Submission to Jurisdiction; Venue: Borrower submits to the jurisdiction
of any state or federal court sitting in Omaha, Nebraska, in any action or
proceeding arising out of or relating to this Agreement and agrees that all
claims in respect of the action or proceeding may be heard and determined in any
such court. Borrower also agrees not to bring any action or proceeding arising
out of or relating to this Agreement in any other court. Borrower waives any
defense of inconvenient forum to the maintenance of any action or proceeding so
brought and waives any bond, surety, or other security that might be required of
Bank. Borrower agrees that a final judgment in any action or proceeding so
brought shall be conclusive and may be enforced by suit on the judgment or in
any other manner provided by law or at equity. Borrower hereby waives any rights
it may have to transfer or change the venue of any suit, action or other
proceeding brought against Borrower by Bank in accordance with this Section or
in connection with this Agreement.


                                        9

<PAGE>

     IN WITNESS WHEREOF, Borrower has caused this Agreement to be executed and
delivered to Bank as of the date set forth above.

                                        "Borrower"

                                        VERASUN ENERGY CORPORATION,
                                        a South Dakota corporation


                                        By:
                                            ------------------------------------
                                        Its:
                                             -----------------------------------


                                       10

<PAGE>

                                   EXHIBIT "A"

                             PERFECTION CERTIFICATE

                             Perfection Certificate
                           (UCC Financing Statements)

     The undersigned, the ___________ of VERASUN ENERGY CORPORATION, a South
Dakota corporation (the "Company"), hereby certifies on behalf of the Company,
with reference to a certain Security Agreement dated as of the same date hereof
(Capitalized terms used herein shall have the meaning ascribed to such terms in
the Security Agreement) between the Company and First National Bank of Omaha, a
national banking association (the "Bank"), to the Bank as follows:

1. NAME. The exact legal name of the Company as that name appears on its
Articles or Certificate of Organization is as follows:

     VERASUN ENERGY CORPORATION

2. OTHER IDENTIFYING FACTORS.

(a) The following is the mailing address of the Company:

     VERASUN ENERGY CORPORATION
     100 22ND AVENUE
     BROOKINGS, SOUTH DAKOTA 57006

(b) If different from its mailing address, the Company's place of business or,
if more than one, its chief executive office is located at the following
address:

Address: _______________________________

City: __________________________________

County: ________________________________

State: _________________________________

Zip Code: ______________________________

(c) The following is the type of organization of the Company:

     CORPORATION


                                       11

<PAGE>

(d) The following is the jurisdiction of the Company's organization:

     SOUTH DAKOTA

(e) The following is the Company's state issued organizational identification
number [state "None" if the state does not issue such a number]: DB050019

3. OTHER NAMES, ETC.

(a) The following is a list of all other names (including trade names or similar
appellations) used by the Company, or any other business or organization to
which the Company became the successor by merger, consolidation, acquisition,
change in form, nature or jurisdiction of organization or otherwise, now or at
any time during the past five years:

(b) Attached to the Agreement as Schedule 1 is the information required in
section 2 for any other business or organization to which the Company became the
successor by merger, consolidation, acquisition, change in form, nature or
jurisdiction of organization or otherwise, now or at any time during the past
five years:

4. OTHER CURRENT LOCATIONS. The following are all other locations in the United
States of America in which the Company maintains any of its Collateral or any
books or records relating to any of the Collateral consisting of accounts,
instruments, chattel paper, general intangibles or mobile goods:

Address: _______________________________

City: __________________________________

County: ________________________________

State: _________________________________

     IN WITNESS WHEREOF, the undersigned has executed this Certificate as of
this 21st day of December, 2005.

                                        VERASUN ENERGY CORPORATION,
                                        A SOUTH DAKOTA CORPORATION


                                        By:
                                            ------------------------------------
                                        Its:
                                             -----------------------------------


                                       12
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "I"

                           AURORA SUBSIDIARY GUARANTY

                                 [See Attached]

<PAGE>
                                                                       EXHIBIT I

                               SUBSIDIARY GUARANTY

     This Subsidiary Guaranty ("Guaranty"), made this 21st day of December,
2005, by VERASUN AURORA CORPORATION, a South Dakota corporation (hereinafter
referred to as "Guarantor"), whose mailing address is 100 22nd Avenue,
Brookings, South Dakota 57006, for the benefit of FIRST NATIONAL BANK OF OMAHA,
a national banking association (hereinafter referred to as the "Bank"), whose
mailing address is 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197.

                                    RECITALS

     WHEREAS, Guarantor is a wholly owned subsidiary of VeraSun Energy
Corporation, a South Dakota corporation (the "Borrower"); and

     WHEREAS, the Borrower has entered into a Revolving Credit Agreement with
Bank of even date herewith (as amended, restated or otherwise modified from time
to time, the "Credit Agreement") pursuant to which Borrower has undertaken
certain covenants and has executed and delivered to Bank an Operating Note of
even date herewith by the Borrower payable to the order of the Bank in the total
principal amount of Thirty Million Dollars ($30,000,000.00) the proceeds of
which may be drawn upon by the Borrower, for the purposes provided for in the
Credit Agreement, in accordance with and subject to the terms and restrictions
contained in the Credit Agreement (the "Note"); and

     WHEREAS, Bank has agreed to provide a Letter of Credit Facility, as defined
in the Credit Agreement, for the benefit of Borrower, whereby Bank, at
Borrower's request and subject to compliance with the terms and provisions of
the Credit Agreement, will issue one or more Letters of Credit, as defined in
the Credit Agreement, in an aggregate principal amount outstanding not to exceed
Ten Million and No/100ths Dollars ($10,000,000.00), on behalf of Borrower,
Guarantor or other Subsidiaries, in accordance with and subject to the terms and
provisions of the Credit Agreement; and

     WHEREAS, Section 2.09 of the Credit Agreement provides that the purposes of
the Credit Agreement include providing the Borrower and the Subsidiaries,
including the Guarantor, with access to (a) operating funds and (b) Letters of
Credit for operating purposes; and

     WHEREAS, Bank has, at Guarantor's previous request, issued letters of
credit for the benefit of certain third-party creditors of the Borrower, the
Guarantor or another Restricted Subsidiary on or prior to the date hereof (the
"Prior Letters of Credit"); and

     WHEREAS, to induce the Bank to enter into the Credit Agreement with the
Borrower and as a condition precedent to the Bank's obligations under the Credit
Agreement, Guarantor has agreed with the Bank to guarantee to the Bank the
Borrower's full and timely performance of all of its covenants, undertakings and
obligations under the provisions of the Credit Agreement, the Note, the Prior
Letters of Credit, the Letters of Credit and any other Loan Documents (as
defined in the Credit Agreement) (this Guaranty, the Credit Agreement, the Note,
the Prior

<PAGE>

Letters of Credit, the Letters of Credit and any other Loan Documents, including
any extensions, modifications, revisions, replacements or restatements thereof,
are herein collectively referred to as the "Guaranty Documents"); and

     WHEREAS, in entering into the Credit Agreement with the Borrower, the Bank
is relying upon Guarantor's agreements and undertakings, as set forth in the
provisions of this Guaranty.

     NOW, THEREFORE, for and in consideration of the Bank's agreement to enter
into the Credit Agreement with the Borrower, and for other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged,
Guarantor hereby agrees as follows:

     SECTION 1. DEFINITIONS. Capitalized terms used in this Guaranty, including
its preamble and recitals, and not otherwise defined herein, shall have the
meaning ascribed thereto in the Credit Agreement.

     SECTION 2. GUARANTY.

     2.1. Guarantor hereby unconditionally and irrevocably guarantees to the
Bank:

          2.1.1. The due and punctual payment in full (and not merely the
     collectibility) of the principal sum due under the Note and all interest
     and any and all other sums now or hereafter accruing thereon, in each case
     when due and payable, whether on any specific payment date or at the stated
     or accelerated maturity of any or all of the Obligations, or otherwise, all
     in accordance with the provisions of the Guaranty Documents; and

          2.1.2. The due and punctual payment in full (and not merely the
     collectibility) of any sums due and payable to Bank as reimbursement for
     Bank's payment of any draw request under any Letter of Credit, including
     but not limited to the Prior Letters of Credit, and all interest and any
     and all other sums now or hereafter accruing thereon, in each case when due
     and payable, all in accordance with the provisions of the Guaranty
     Documents; and

          2.1.3. The due and punctual payment in full (and not merely the
     collectibility) of each other sum or charge that at any time becomes due
     and payable in accordance with the provisions of any other Guaranty
     Documents; and

          2.1.4. The due and punctual performance (and not merely the
     enforceability) of all of the Borrower's other obligations under the
     provisions of the Guaranty Documents; and

          2.1.5. The due and punctual payment in full (and not merely the
     collectibility) of any and all loss, damages, or expenses incurred by the
     Bank and arising out of any default by the Borrower in performing any of
     its obligations under any of the Guaranty Documents.


                                        2

<PAGE>

     2.2. If the Borrower fails duly and punctually to pay any of such sum(s),
the Guarantor shall forthwith pay the same, together with interest thereon from
the date on which payment thereof by the Borrower became due at the Default Rate
of Interest, as provided in the Note with respect to the Borrower.

     SECTION 3. SECURITY. The Guarantor's obligations hereunder shall be secured
by (a) the Subsidiary Security Agreement dated the same date hereof executed and
delivered to the Bank by the Guarantor in the form attached hereto as Exhibit
"A" and incorporated herein by this reference and (b) the Control Agreement
dated the same date hereof executed and delivered to the Bank by the Guarantor
in the form attached hereto as Exhibit "B" and incorporated herein by this
reference.

     SECTION 4. CERTAIN RIGHTS OF BANK. The Bank may, in the exercise of its
sole and absolute discretion without providing notice to, or obtaining the
consent of, Guarantor, and without in any way releasing, altering, or impairing
any of Guarantor's obligations and liabilities under this Guaranty, from time to
time:

     4.1. Waive compliance with or any default occurring under, or grant any
other indulgence with respect to, any of the Guaranty Documents;

     4.2. Modify, revise, replace or otherwise supplement any of the provisions
of the Guaranty Documents other than this Guaranty;

     4.3. Grant any extension or renewal of or with respect to any of the
Guaranty Documents, and/or effect any release, compromise, or settlement in
connection therewith;

     4.4. Advance any sum if the Bank deems it necessary or advisable in its
reasonable credit judgment to perform any term or covenant, or satisfy any
condition, set forth in the provisions of any of the Guaranty Documents;

     4.5. Assign or otherwise transfer all or any portion of any of the Guaranty
Documents or any interest of the Bank therein and Guarantor agrees not to assert
against any such assignee or assignee's assigns, any defense, set-off,
recoupment claim or counterclaim which Guarantor has or may at any time have
against Bank for any reason whatsoever, except for payment of the Obligations.
Guarantor agrees that if Guarantor receives written notice of an assignment from
Bank, Guarantor will pay all amounts payable under this Guaranty to such
assignee or as instructed by Bank. Guarantor also agrees to confirm in writing
receipt of the notice of assignment as may be reasonably requested by Bank or
assignee;

     4.6. Deal in all respects with the Borrower as if this Guaranty were not in
effect; and

     4.7. Agree to the substitution, sale, transfer, exchange, release or other
disposition of any or all of the Collateral or any of the Guaranty Documents.


                                        3

<PAGE>

     SECTION 5. LIABILITY OF GUARANTOR.

     5.1. Guarantor's liability under the provisions of this Guaranty (a) shall
be primary, direct, unconditional, irrevocable and immediate, and (b) shall not
be conditioned or contingent upon the Bank's pursuit of any remedy that it has,
or may have, against the Borrower or any other person with respect to any of the
Guaranty Documents, pursuant to the provisions thereof or at law or in equity,
or of the adequacy of any consideration or security given therefore or in
connection therewith, or of any other circumstance that might otherwise
constitute a legal or equitable discharge of a surety or a guarantor under
applicable law. To the extent permitted by applicable law, Guarantor hereby
waives any and all defenses at law or in equity that may be available to such
Guarantor by virtue of any such circumstance.

     5.2. Without limiting the generality of the foregoing provisions of this
Section 5, the Bank shall not be required (a) to make any demand of the Borrower
or any other person, or (b) otherwise to pursue or exhaust its remedies against
the Borrower or any other person or against any or all of the Collateral
(including any other property by which the Obligations may hereafter in any
manner be secured), before, simultaneously with, or after enforcing any of the
Bank's rights and remedies under this Guaranty against Guarantor. Any one or
more successive and/or concurrent actions may be brought hereon against
Guarantor, either as part of any action brought against the Borrower, or in one
or more separate actions, as often as the Bank deems advisable in the exercise
of its sole and absolute discretion.

     5.3. Guarantor's liability under the provisions of this Guaranty shall
continue after any assignment or transfer by the Borrower or the Bank of any of
its rights under any of the Guaranty Documents or in the Collateral.

     SECTION 6. GUARANTOR'S REPRESENTATIONS, WARRANTIES AND COVENANTS. Guarantor
hereby represents, warrants, and covenants to the Bank as follows,

          6.1.1. The Guarantor is duly authorized to (a) execute and deliver
     this Guaranty and each of the Guaranty Documents executed or to be executed
     by the Guarantor, (b) perform the covenants herein and therein contained,
     (c) consummate the transactions contemplated hereby and thereby; and all
     required actions in respect to the foregoing have been taken;

          6.1.2. The execution, delivery, and performance of this Guaranty will
     not (a) violate any provision of any law, rule, regulation (including,
     without limitation, Regulations U and X of the Board of Governors of the
     Federal Reserve System), order, writ, judgment, injunction, decree,
     determination, or award presently in effect having applicability to
     Guarantor; (b) result in a breach of or constitute a default under any
     indenture or loan or credit agreement or any other material agreement,
     lease, or instrument to which Guarantor is a party or by which Guarantor or
     Guarantor's properties may be bound or affected; or (c) result in, or
     require, the creation or imposition of any encumbrance, upon or with
     respect to any of the properties now owned or hereafter acquired by
     Guarantor (except in favor of the Bank);


                                        4

<PAGE>

          6.1.3. This Guaranty, and each of the Guaranty Documents executed by
     the Guarantor, is the legal, valid, and binding obligation of the
     Guarantor, and enforceable against the Guarantor in accordance with the
     terms hereof and thereof except to the extent that such enforcement may be
     limited by applicable bankruptcy, insolvency, and other similar laws
     affecting creditors' rights generally;

          6.1.4. No information, exhibit, or report furnished by the Guarantor
     in connection with the negotiation of any of the Guaranty Documents
     contained any material misstatement of fact or omitted to state a material
     fact necessary to make the statement contained therein not materially
     misleading;

          6.1.5. There is no pending or, to the Guarantor's knowledge,
     threatened action or proceeding against or affecting the Guarantor before
     any court, governmental agency, or arbitrator which may, in any one case or
     in the aggregate, materially adversely affect the financial condition,
     operations, properties, or business of the Guarantor or the ability of the
     Guarantor to perform its obligation under the Guaranty Documents to which
     it is a party; and

          6.1.6. The Guarantor is not in default in any material respect with
     respect to any judgment, writ, injunction, decree, rule, or regulation of
     any court, arbitrator, or federal, state, municipal, or other governmental
     authority, commission, board, bureau, agency or instrumentality, domestic
     or foreign, applicable to, or with jurisdiction over, Guarantor.

     SECTION 7. WAIVERS.

     7.1. Guarantor hereby expressly waives, to the fullest extent permitted
under applicable law:

          7.1.1. Presentment and demand for payment of any sum(s) payable under
     the provisions of the Guaranty Documents and all extensions, modifications,
     revisions, replacements and restatements thereof, and protest of any
     nonpayment thereof;

          7.1.2. Notice of acceptance of this Guaranty and of such presentment,
     demand and protest;

          7.1.3. Notice of any default under this Guaranty or under the
     provisions of any of the Guaranty Documents and all extensions,
     modifications, revisions, replacements and restatements thereof, and of any
     indulgence with respect thereto;

          7.1.4. Demand for observance or performance, and enforcement, of any
     of the terms or conditions of this Guaranty, and/or any of the other
     Guaranty Documents and all extensions, modifications, revisions,
     replacements and restatements thereof;


                                        5

<PAGE>

          7.1.5. Any and all other notices and demands that may otherwise be
     required by law to be given or made; and

          7.1.6. ANY AND ALL RIGHTS THAT SUCH GUARANTOR MAY HAVE TO A TRIAL BY
     JURY IN ANY ACTION BROUGHT ON OR WITH RESPECT TO THIS GUARANTY.

     7.2. Guarantor hereby expressly agrees that if this Guaranty is enforced by
suit or otherwise, or if the Bank exercises any of its rights or remedies under
the provisions of any of the Guaranty Documents upon any default by the Borrower
in performing any of its obligations thereunder, the Guarantor will reimburse
the Bank, upon demand, for any and all reasonable out-of-pocket expenses that it
incurs in connection therewith (including, by way of example rather than of
limitation, reasonable attorneys' fees and costs).

     7.3. If any payment applied by the Bank to the Obligations is thereafter
set aside, recovered, rescinded, or required to be returned for any reason
(including without limitation, the bankruptcy, insolvency, or reorganization of
the Borrower or any other person or entity) the Obligations to which such
payment was applied shall for purposes of this Guaranty be deemed to have
continued in existence, notwithstanding such application, and this Guaranty
shall be enforceable as fully as if such application had not been made.

     SECTION 8. BANKRUPTCY OR INSOLVENCY.

     8.1. Anything contained in any of the provisions of this Guaranty or any of
the other Guaranty Documents to the contrary notwithstanding, the Bank may, in
the exercise of its sole and absolute discretion, accelerate the debt evidenced
and secured by the Guaranty Documents, if any of the following events shall
occur:

          8.1.1. Guarantor (a) applies for or consents to the appointment of a
     receiver, trustee, or liquidator of Guarantor or of all or a substantial
     part of Guarantor's assets, (b) files a voluntary petition in bankruptcy,
     or admits in writing inability to pay Guarantor's debts as they come due,
     (c) makes an assignment for the benefit of creditors, (d) files a petition
     or an answer seeking a reorganization or an arrangement with creditors or
     seeking to take advantage of any insolvency law, or (e) files an answer
     admitting the material allegations of a petition filed against Guarantor in
     any bankruptcy, reorganization, or insolvency proceeding; or

          8.1.2. (a) An order, judgment or decree is entered by any court of
     competent jurisdiction adjudicating Guarantor a bankrupt or an insolvent,
     or approving a petition seeking such a reorganization, or appointing a
     receiver, trustee, or liquidator of Guarantor or of all or a substantial
     part of Guarantor's assets, or (b) there otherwise commences, with respect
     to Guarantor or any of Guarantor's assets, any proceeding under any
     bankruptcy, reorganization, arrangement, insolvency, readjustment,
     receivership, or like law or statute, and if in either case such order,
     judgment, decree or proceeding continues unstayed for a period of sixty
     (60) consecutive days.


                                        6

<PAGE>

     8.2. Nothing in the provisions of this Section 8 shall be deemed in any way
to alter or impair any right that the Bank may have under the provisions of the
Note, the Prior Letters of Credit, the Letters of Credit or any of the other
Guaranty Documents to accelerate any debt or obligation on the occurrence of any
default or other event provided therein and entitling the Bank to accelerate
such debt or obligation, whether or not relating to Guarantor.

     SECTION 9. CERTAIN RIGHTS OF GUARANTOR.

     9.1. If Guarantor advances, or at this time has advanced, any sum to the
Borrower, or if the Borrower in any other manner is, or becomes, indebted to
Guarantor, such sum and debt shall be subordinate in all respects to any and all
amounts now or hereafter due and owing to the Bank under the provisions of any
of the Guaranty Documents.

     9.2. Anything contained in any provisions of this Guaranty, the Guaranty
Documents, or applicable law to the contrary notwithstanding, the Guarantor
shall not have any right of subrogation in or to any of the Bank's rights under
the provisions of this Guaranty, the Note, the Prior Letters of Credit, the
Letters of Credit or any of the other Guaranty Documents unless and until all
amounts now or hereafter owed to the Bank as guaranteed hereunder and under the
provisions of the Note, the Prior Letters of Credit, the Letters of Credit and
all of the other Guaranty Documents (including, by way of example rather than of
limitation, the entire principal of the Obligations and any and all interest
accruing thereon, regardless of whether, at the time in question, any one or
more installments thereof are not yet due and payable under the provisions of
the Note) are paid in full.

     SECTION 10. EFFECT OF THIS GUARANTY. Guarantor hereby represents and
warrants to the Bank that such Guarantor (a) is a wholly owned subsidiary of the
Borrower; (b) will be directly and materially benefited by the Loans by
receiving or having access to, in accordance with the terms and provisions of
the Credit Agreement, additional operating funds from Borrower as a result of
such Loans; (c) will be directly and materially benefited by the Letter of
Credit Facility by receiving or having access to, in accordance with the terms
and provisions of the Credit Agreement, Letters of Credit for the Guarantor's
operations; (d) has examined, or has had an opportunity to examine, this
Guaranty, the Credit Agreement, the Note, the Prior Letters of Credit, the
Letters of Credit, the Security Agreement, the Subsidiary Security Agreement,
the Control Agreements, and each of the other Guaranty Documents; and (e) is
represented, and in the negotiations of the terms and provisions of this
Guaranty and the Guaranty Documents has been represented, by counsel of
Guarantor's own selection relating to the terms and provisions thereof.

     SECTION 11. NOTICES, ETC. All notices and other communications provided for
under this Guaranty and under the other Guaranty Documents to which the
Guarantor is a party shall be in writing (including facsimile transmissions) and
mailed or transmitted or delivered, if to the Guarantor, at its address at 100
22nd Avenue, Brookings, South Dakota 57006, Attention: Bruce Jamerson, and if to
the Bank, at its address at 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197,
Attention: Natalie E. Mason; or, as to each party, at such other address as
shall be designated by such party in a written notice to the other party
complying as to delivery with the


                                        7

<PAGE>

terms of this Section 11. Except as otherwise provided in this Agreement, all
such notices and communications shall be effective when deposited in the U.S.
mail and addressed as aforesaid, except that notices to the Bank pursuant to the
provisions of this Section 11 shall not be effective until received by the Bank.

     SECTION 12. GENERAL.

     12.1. Amendment. This Guaranty may be amended or supplemented only by an
instrument executed and delivered by Guarantor and the Bank.

     12.2. Waiver. No party hereto shall be deemed to have waived the exercise
of any right which it holds under this Guaranty, unless that waiver is made
expressly and in writing (and no delay or omission by any party hereto in
exercising any such right shall be deemed a waiver of its future exercise). No
such waiver made as to any instance involving the exercise of any such right
shall be deemed a waiver as to any other such instance, or any other such right.

     12.3. Applicable Law. This Guaranty shall be governed by, and construed in
accordance with, the laws of the State of Nebraska without giving effect to any
choice or conflict of law provision or rule (whether of the State of Nebraska or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Nebraska.

     12.4. Submission to Jurisdiction; Venue. To induce the Bank to enter into
this Guaranty, the Guarantor irrevocably agrees that, subject to the Bank's sole
and absolute election, all suits, actions or other proceedings in any way,
manner or respect, arising out of or from or related to this Guaranty, the
Credit Agreement, the Note, the Prior Letters of Credit, the Letters of Credit,
the Security Agreement, the Control Agreement, or any of the other Guaranty
Documents, shall be subject to litigation in courts having situs within
Nebraska. The Guarantor hereby consents and submits to the jurisdiction of any
local, state, or federal court located within the State of Nebraska. The
Guarantor hereby waives any rights it may have to transfer or change the venue
of any suit, action or other proceeding brought against the Guarantor by the
Bank in accordance with this Section or in connection with this Guaranty.

     12.5. Time of Essence. Time shall be of the essence of this Guaranty.

     12.6. Headings. The headings of the sections, subsections, paragraphs, and
subparagraphs of this Guaranty are provided herein, for and only for,
convenience of reference, and shall not be considered in construing their
contents.

     12.7. Construction. As used in this Guaranty, (a) the term "person" means a
natural person, a trustee, a corporation, a partnership, a limited liability
company, and any other form of legal entity; and (b) all references made (i) in
the neuter, masculine, or feminine gender shall be deemed to have been made in
all such genders; (ii) in the singular or plural number shall be deemed to have
been made, respectively, in the plural or singular number as well; (iii) to any
section, subsection, paragraph or subparagraph shall, unless therein expressly
indicated to the contrary, be deemed to have been made to such section,
subsection, paragraph or subparagraph of


                                        8

<PAGE>

this Guaranty; and (iv) to the Guarantor, the Bank, or the Borrower shall be
deemed to refer to each person hereinabove so named, and their respective heirs,
personal representatives, successors and permitted assigns.

     12.8. Exhibits and Recitals. Each writing referred to in this Guaranty as
being attached hereto as an exhibit or otherwise referred to herein or
designated in this Guaranty, whether or not as an exhibit hereto, is hereby
incorporated herein and made a part of this Guaranty. The recitals contained
above are incorporated herein and made a part of this Guaranty by this
reference.

     12.9. Severability. No determination by any court or governmental body that
any provision of this Guaranty, or any amendment hereof, is invalid or
unenforceable in any instance shall affect the validity or enforceability of (a)
any other such provisions, or (b) such provisions in any circumstance not
controlled by such determination. Each such provision shall be valid and
enforceable to the fullest extent allowed by, and shall be construed wherever
possible as being consistent with, applicable law.

     12.10. Assignment. This Guaranty shall be binding upon and shall inure to
the benefit of the parties hereto and their respective heirs, personal
representatives, successors and permitted assigns hereunder, provided however,
that Guarantor may not assign any of its obligations hereunder to any other
person without the prior written consent of Bank, which consent may be withheld
in the Bank's sole discretion.

     12.11. Complete Understanding. This Guaranty represents the complete
understanding between the parties hereto as to the subject matter hereof, and
supersedes all prior negotiations, representations, warranties, statements or
agreements, either written or oral, between or among the parties hereto as to
the same, except as the same may be included in one or more of the Guaranty
Documents.

     IN WITNESS WHEREOF, Guarantor has executed this Guaranty and delivered this
Guaranty to the Bank the day and year first above written.

                                        "Guarantor"

                                        VERASUN AURORA CORPORATION,
                                        a South Dakota corporation


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        9

<PAGE>

                                   EXHIBIT "A"

                          SUBSIDIARY SECURITY AGREEMENT

                               [See the attached.]


                                       10

<PAGE>

                                   EXHIBIT "B"

                                CONTROL AGREEMENT

                               [See the attached.]


                                       11
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "J"

                        CHARLES CITY SUBSIDIARY GUARANTY

                                 [See Attached]


<PAGE>
                                                                       EXHIBIT J

                               SUBSIDIARY GUARANTY

     This Subsidiary Guaranty ("Guaranty"), made this 21st day of December,
2005, by VERASUN CHARLES CITY, LLC, a Delaware limited liability company
(hereinafter referred to as "Guarantor"), whose mailing address is 100 22nd
Avenue, Brookings, South Dakota 57006, for the benefit of FIRST NATIONAL BANK OF
OMAHA, a national banking association (hereinafter referred to as the "Bank"),
whose mailing address is 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197.

                                    RECITALS

     WHEREAS, Guarantor is a wholly owned subsidiary of VeraSun Energy
Corporation, a South Dakota corporation (the "Borrower"); and

     WHEREAS, the Borrower has entered into a Revolving Credit Agreement with
Bank of even date herewith (as amended, restated or otherwise modified from time
to time, the "Credit Agreement") pursuant to which Borrower has undertaken
certain covenants and has executed and delivered to Bank an Operating Note of
even date herewith by the Borrower payable to the order of the Bank in the total
principal amount of Thirty Million Dollars ($30,000,000.00) the proceeds of
which may be drawn upon by the Borrower, for the purposes provided for in the
Credit Agreement, in accordance with and subject to the terms and restrictions
contained in the Credit Agreement (the "Note"); and

     WHEREAS, Bank has agreed to provide a Letter of Credit Facility, as defined
in the Credit Agreement, for the benefit of Borrower, whereby Bank, at
Borrower's request and subject to compliance with the terms and provisions of
the Credit Agreement, will issue one or more Letters of Credit, as defined in
the Credit Agreement, in an aggregate principal amount outstanding not to exceed
Ten Million and No/100ths Dollars ($10,000,000.00), on behalf of Borrower,
Guarantor or other Subsidiaries, in accordance with and subject to the terms and
provisions of the Credit Agreement; and

     WHEREAS, Section 2.09 of the Credit Agreement provides that the purposes of
the Credit Agreement include providing the Borrower and the Subsidiaries,
including the Guarantor, with access to (a) operating funds and (b) Letters of
Credit for operating purposes; and

     WHEREAS, to induce the Bank to enter into the Credit Agreement with the
Borrower and as a condition precedent to the Bank's obligations under the Credit
Agreement, Guarantor has agreed with the Bank to guarantee to the Bank the
Borrower's full and timely performance of all of its covenants, undertakings and
obligations under the provisions of the Credit Agreement, the Note, the Letters
of Credit and any other Loan Documents (as defined in the Credit Agreement)
(this Guaranty, the Credit Agreement, the Note, the Letters of Credit and any
other Loan Documents, including any extensions, modifications, revisions,
replacements or restatements thereof, are herein collectively referred to as the
"Guaranty Documents"); and

<PAGE>

     WHEREAS, in entering into the Credit Agreement with the Borrower, the Bank
is relying upon Guarantor's agreements and undertakings, as set forth in the
provisions of this Guaranty.

     NOW, THEREFORE, for and in consideration of the Bank's agreement to enter
into the Credit Agreement with the Borrower, and for other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged,
Guarantor hereby agrees as follows:

     SECTION 1. DEFINITIONS. Capitalized terms used in this Guaranty, including
its preamble and recitals, and not otherwise defined herein, shall have the
meaning ascribed thereto in the Credit Agreement.

     SECTION 2. GUARANTY.

     2.1. Guarantor hereby unconditionally and irrevocably guarantees to the
Bank:

          2.1.1. The due and punctual payment in full (and not merely the
     collectibility) of the principal sum due under the Note and all interest
     and any and all other sums now or hereafter accruing thereon, in each case
     when due and payable, whether on any specific payment date or at the stated
     or accelerated maturity of any or all of the Obligations, or otherwise, all
     in accordance with the provisions of the Guaranty Documents; and

          2.1.2. The due and punctual payment in full (and not merely the
     collectibility) of any sums due and payable to Bank as reimbursement for
     Bank's payment of any draw request under any Letter of Credit and all
     interest and any and all other sums now or hereafter accruing thereon, in
     each case when due and payable, all in accordance with the provisions of
     the Guaranty Documents; and

          2.1.3. The due and punctual payment in full (and not merely the
     collectibility) of each other sum or charge that at any time becomes due
     and payable in accordance with the provisions of any other Guaranty
     Documents; and

          2.1.4. The due and punctual performance (and not merely the
     enforceability) of all of the Borrower's other obligations under the
     provisions of the Guaranty Documents; and

          2.1.5. The due and punctual payment in full (and not merely the
     collectibility) of any and all loss, damages, or expenses incurred by the
     Bank and arising out of any default by the Borrower in performing any of
     its obligations under any of the Guaranty Documents.

     2.2. If the Borrower fails duly and punctually to pay any of such sum(s),
the Guarantor shall forthwith pay the same, together with interest thereon from
the date on which payment thereof by the Borrower became due at the Default Rate
of Interest, as provided in the Note with respect to the Borrower.


                                        2

<PAGE>

     SECTION 3. SECURITY. The Guarantor's obligations hereunder shall be secured
by (a) the Subsidiary Security Agreement dated the same date hereof executed and
delivered to the Bank by the Guarantor in the form attached hereto as Exhibit
"A" and incorporated herein by this reference and (b) the Control Agreement
dated the same date hereof executed and delivered to the Bank by the Guarantor
in the form attached hereto as Exhibit "B" and incorporated herein by this
reference.

     SECTION 4. CERTAIN RIGHTS OF BANK. The Bank may, in the exercise of its
sole and absolute discretion without providing notice to, or obtaining the
consent of, Guarantor, and without in any way releasing, altering, or impairing
any of Guarantor's obligations and liabilities under this Guaranty, from time to
time:

     4.1. Waive compliance with or any default occurring under, or grant any
other indulgence with respect to, any of the Guaranty Documents;

     4.2. Modify, revise, replace or otherwise supplement any of the provisions
of the Guaranty Documents other than this Guaranty;

     4.3. Grant any extension or renewal of or with respect to any of the
Guaranty Documents, and/or effect any release, compromise, or settlement in
connection therewith;

     4.4. Advance any sum if the Bank deems it necessary or advisable in its
reasonable credit judgment to perform any term or covenant, or satisfy any
condition, set forth in the provisions of any of the Guaranty Documents;

     4.5. Assign or otherwise transfer all or any portion of any of the Guaranty
Documents or any interest of the Bank therein and Guarantor agrees not to assert
against any such assignee or assignee's assigns, any defense, set-off,
recoupment claim or counterclaim which Guarantor has or may at any time have
against Bank for any reason whatsoever, except for payment of the Obligations.
Guarantor agrees that if Guarantor receives written notice of an assignment from
Bank, Guarantor will pay all amounts payable under this Guaranty to such
assignee or as instructed by Bank. Guarantor also agrees to confirm in writing
receipt of the notice of assignment as may be reasonably requested by Bank or
assignee;

     4.6. Deal in all respects with the Borrower as if this Guaranty were not in
effect; and

     4.7. Agree to the substitution, sale, transfer, exchange, release or other
disposition of any or all of the Collateral or any of the Guaranty Documents.

     SECTION 5. LIABILITY OF GUARANTOR.

     5.1. Guarantor's liability under the provisions of this Guaranty (a) shall
be primary, direct, unconditional, irrevocable and immediate, and (b) shall not
be conditioned or contingent upon the Bank's pursuit of any remedy that it has,
or may have, against the Borrower or any other person with respect to any of the
Guaranty Documents, pursuant to the provisions thereof or at


                                        3

<PAGE>

law or in equity, or of the adequacy of any consideration or security given
therefore or in connection therewith, or of any other circumstance that might
otherwise constitute a legal or equitable discharge of a surety or a guarantor
under applicable law. To the extent permitted by applicable law, Guarantor
hereby waives any and all defenses at law or in equity that may be available to
such Guarantor by virtue of any such circumstance.

     5.2. Without limiting the generality of the foregoing provisions of this
Section 5, the Bank shall not be required (a) to make any demand of the Borrower
or any other person, or (b) otherwise to pursue or exhaust its remedies against
the Borrower or any other person or against any or all of the Collateral
(including any other property by which the Obligations may hereafter in any
manner be secured), before, simultaneously with, or after enforcing any of the
Bank's rights and remedies under this Guaranty against Guarantor. Any one or
more successive and/or concurrent actions may be brought hereon against
Guarantor, either as part of any action brought against the Borrower, or in one
or more separate actions, as often as the Bank deems advisable in the exercise
of its sole and absolute discretion.

     5.3. Guarantor's liability under the provisions of this Guaranty shall
continue after any assignment or transfer by the Borrower or the Bank of any of
its rights under any of the Guaranty Documents or in the Collateral.

     SECTION 6. GUARANTOR'S REPRESENTATIONS, WARRANTIES AND COVENANTS. Guarantor
hereby represents, warrants, and covenants to the Bank as follows,

          6.1.1. The Guarantor is duly authorized to (a) execute and deliver
     this Guaranty and each of the Guaranty Documents executed or to be executed
     by the Guarantor, (b) perform the covenants herein and therein contained,
     (c) consummate the transactions contemplated hereby and thereby; and all
     required actions in respect to the foregoing have been taken;

          6.1.2. The execution, delivery, and performance of this Guaranty will
     not (a) violate any provision of any law, rule, regulation (including,
     without limitation, Regulations U and X of the Board of Governors of the
     Federal Reserve System), order, writ, judgment, injunction, decree,
     determination, or award presently in effect having applicability to
     Guarantor; (b) result in a breach of or constitute a default under any
     indenture or loan or credit agreement or any other material agreement,
     lease, or instrument to which Guarantor is a party or by which Guarantor or
     Guarantor's properties may be bound or affected; or (c) result in, or
     require, the creation or imposition of any encumbrance, upon or with
     respect to any of the properties now owned or hereafter acquired by
     Guarantor (except in favor of the Bank);

          6.1.3. This Guaranty, and each of the Guaranty Documents executed by
     the Guarantor, is the legal, valid, and binding obligation of the
     Guarantor, and enforceable against the Guarantor in accordance with the
     terms hereof and thereof except to the extent that such enforcement may be
     limited by applicable bankruptcy, insolvency, and other similar laws
     affecting creditors' rights generally;


                                        4

<PAGE>

          6.1.4. No information, exhibit, or report furnished by the Guarantor
     in connection with the negotiation of any of the Guaranty Documents
     contained any material misstatement of fact or omitted to state a material
     fact necessary to make the statement contained therein not materially
     misleading;

          6.1.5. There is no pending or, to the Guarantor's knowledge,
     threatened action or proceeding against or affecting the Guarantor before
     any court, governmental agency, or arbitrator which may, in any one case or
     in the aggregate, materially adversely affect the financial condition,
     operations, properties, or business of the Guarantor or the ability of the
     Guarantor to perform its obligation under the Guaranty Documents to which
     it is a party; and

          6.1.6. The Guarantor is not in default in any material respect with
     respect to any judgment, writ, injunction, decree, rule, or regulation of
     any court, arbitrator, or federal, state, municipal, or other governmental
     authority, commission, board, bureau, agency or instrumentality, domestic
     or foreign, applicable to, or with jurisdiction over, Guarantor.

     SECTION 7. WAIVERS.

     7.1. Guarantor hereby expressly waives, to the fullest extent permitted
under applicable law:

          7.1.1. Presentment and demand for payment of any sum(s) payable under
     the provisions of the Guaranty Documents and all extensions, modifications,
     revisions, replacements and restatements thereof, and protest of any
     nonpayment thereof;

          7.1.2. Notice of acceptance of this Guaranty and of such presentment,
     demand and protest;

          7.1.3. Notice of any default under this Guaranty or under the
     provisions of any of the Guaranty Documents and all extensions,
     modifications, revisions, replacements and restatements thereof, and of any
     indulgence with respect thereto;

          7.1.4. Demand for observance or performance, and enforcement, of any
     of the terms or conditions of this Guaranty, and/or any of the other
     Guaranty Documents and all extensions, modifications, revisions,
     replacements and restatements thereof;

          7.1.5. Any and all other notices and demands that may otherwise be
     required by law to be given or made; and

          7.1.6. ANY AND ALL RIGHTS THAT SUCH GUARANTOR MAY HAVE TO A TRIAL BY
     JURY IN ANY ACTION BROUGHT ON OR WITH RESPECT TO THIS GUARANTY.


                                        5

<PAGE>

     7.2. Guarantor hereby expressly agrees that if this Guaranty is enforced by
suit or otherwise, or if the Bank exercises any of its rights or remedies under
the provisions of any of the Guaranty Documents upon any default by the Borrower
in performing any of its obligations thereunder, the Guarantor will reimburse
the Bank, upon demand, for any and all reasonable out-of-pocket expenses that it
incurs in connection therewith (including, by way of example rather than of
limitation, reasonable attorneys' fees and costs).

     7.3. If any payment applied by the Bank to the Obligations is thereafter
set aside, recovered, rescinded, or required to be returned for any reason
(including without limitation, the bankruptcy, insolvency, or reorganization of
the Borrower or any other person or entity) the Obligations to which such
payment was applied shall for purposes of this Guaranty be deemed to have
continued in existence, notwithstanding such application, and this Guaranty
shall be enforceable as fully as if such application had not been made.

     SECTION 8. BANKRUPTCY OR INSOLVENCY.

     8.1. Anything contained in any of the provisions of this Guaranty or any of
the other Guaranty Documents to the contrary notwithstanding, the Bank may, in
the exercise of its sole and absolute discretion, accelerate the debt evidenced
and secured by the Guaranty Documents, if any of the following events shall
occur:

          8.1.1. Guarantor (a) applies for or consents to the appointment of a
     receiver, trustee, or liquidator of Guarantor or of all or a substantial
     part of Guarantor's assets, (b) files a voluntary petition in bankruptcy,
     or admits in writing inability to pay Guarantor's debts as they come due,
     (c) makes an assignment for the benefit of creditors, (d) files a petition
     or an answer seeking a reorganization or an arrangement with creditors or
     seeking to take advantage of any insolvency law, or (e) files an answer
     admitting the material allegations of a petition filed against Guarantor in
     any bankruptcy, reorganization, or insolvency proceeding; or

          8.1.2. (a) An order, judgment or decree is entered by any court of
     competent jurisdiction adjudicating Guarantor a bankrupt or an insolvent,
     or approving a petition seeking such a reorganization, or appointing a
     receiver, trustee, or liquidator of Guarantor or of all or a substantial
     part of Guarantor's assets, or (b) there otherwise commences, with respect
     to Guarantor or any of Guarantor's assets, any proceeding under any
     bankruptcy, reorganization, arrangement, insolvency, readjustment,
     receivership, or like law or statute, and if in either case such order,
     judgment, decree or proceeding continues unstayed for a period of sixty
     (60) consecutive days.

     8.2. Nothing in the provisions of this Section 8 shall be deemed in any way
to alter or impair any right that the Bank may have under the provisions of the
Note, the Letters of Credit or any of the other Guaranty Documents to accelerate
any debt or obligation on the occurrence of any default or other event provided
therein and entitling the Bank to accelerate such debt or obligation, whether or
not relating to Guarantor.


                                        6

<PAGE>

     SECTION 9. CERTAIN RIGHTS OF GUARANTOR.

     9.1. If Guarantor advances, or at this time has advanced, any sum to the
Borrower, or if the Borrower in any other manner is, or becomes, indebted to
Guarantor, such sum and debt shall be subordinate in all respects to any and all
amounts now or hereafter due and owing to the Bank under the provisions of any
of the Guaranty Documents.

     9.2. Anything contained in any provisions of this Guaranty, the Guaranty
Documents, or applicable law to the contrary notwithstanding, the Guarantor
shall not have any right of subrogation in or to any of the Bank's rights under
the provisions of this Guaranty, the Note, the Letters of Credit or any of the
other Guaranty Documents unless and until all amounts now or hereafter owed to
the Bank as guaranteed hereunder and under the provisions of the Note, the
Letters of Credit and all of the other Guaranty Documents (including, by way of
example rather than of limitation, the entire principal of the Obligations and
any and all interest accruing thereon, regardless of whether, at the time in
question, any one or more installments thereof are not yet due and payable under
the provisions of the Note) are paid in full.

     SECTION 10. EFFECT OF THIS GUARANTY. Guarantor hereby represents and
warrants to the Bank that such Guarantor (a) is a wholly owned subsidiary of the
Borrower; (b) will be directly and materially benefited by the Loans by
receiving or having access to, in accordance with the terms and provisions of
the Credit Agreement, additional operating funds from Borrower as a result of
such Loans; (c) will be directly and materially benefited by the Letter of
Credit Facility by receiving or having access to, in accordance with the terms
and provisions of the Credit Agreement, Letters of Credit for the Guarantor's
operations; (d) has examined, or has had an opportunity to examine, this
Guaranty, the Credit Agreement, the Note, the Letters of Credit, the Security
Agreement, the Subsidiary Security Agreement, the Control Agreements, and each
of the other Guaranty Documents; and (e) is represented, and in the negotiations
of the terms and provisions of this Guaranty and the Guaranty Documents has been
represented, by counsel of Guarantor's own selection relating to the terms and
provisions thereof.

     SECTION 11. NOTICES, ETC. All notices and other communications provided for
under this Guaranty and under the other Guaranty Documents to which the
Guarantor is a party shall be in writing (including facsimile transmissions) and
mailed or transmitted or delivered, if to the Guarantor, at its address at 100
22nd Avenue, Brookings, South Dakota 57006, Attention: Bruce Jamerson, and if to
the Bank, at its address at 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197,
Attention: Natalie E. Mason; or, as to each party, at such other address as
shall be designated by such party in a written notice to the other party
complying as to delivery with the terms of this Section 11. Except as otherwise
provided in this Agreement, all such notices and communications shall be
effective when deposited in the U.S. mail and addressed as aforesaid, except
that notices to the Bank pursuant to the provisions of this Section 11 shall not
be effective until received by the Bank.


                                        7

<PAGE>

     SECTION 12. GENERAL.

     12.1. Amendment. This Guaranty may be amended or supplemented only by an
instrument executed and delivered by Guarantor and the Bank.

     12.2. Waiver. No party hereto shall be deemed to have waived the exercise
of any right which it holds under this Guaranty, unless that waiver is made
expressly and in writing (and no delay or omission by any party hereto in
exercising any such right shall be deemed a waiver of its future exercise). No
such waiver made as to any instance involving the exercise of any such right
shall be deemed a waiver as to any other such instance, or any other such right.

     12.3. Applicable Law. This Guaranty shall be governed by, and construed in
accordance with, the laws of the State of Nebraska without giving effect to any
choice or conflict of law provision or rule (whether of the State of Nebraska or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Nebraska.

     12.4. Submission to Jurisdiction; Venue. To induce the Bank to enter into
this Guaranty, the Guarantor irrevocably agrees that, subject to the Bank's sole
and absolute election, all suits, actions or other proceedings in any way,
manner or respect, arising out of or from or related to this Guaranty, the
Credit Agreement, the Note, the Letters of Credit, the Security Agreement, the
Control Agreement, or any of the other Guaranty Documents, shall be subject to
litigation in courts having situs within Nebraska. The Guarantor hereby consents
and submits to the jurisdiction of any local, state, or federal court located
within the State of Nebraska. The Guarantor hereby waives any rights it may have
to transfer or change the venue of any suit, action or other proceeding brought
against the Guarantor by the Bank in accordance with this Section or in
connection with this Guaranty.

     12.5. Time of Essence. Time shall be of the essence of this Guaranty.

     12.6. Headings. The headings of the sections, subsections, paragraphs, and
subparagraphs of this Guaranty are provided herein, for and only for,
convenience of reference, and shall not be considered in construing their
contents.

     12.7. Construction. As used in this Guaranty, (a) the term "person" means a
natural person, a trustee, a corporation, a partnership, a limited liability
company, and any other form of legal entity; and (b) all references made (i) in
the neuter, masculine, or feminine gender shall be deemed to have been made in
all such genders; (ii) in the singular or plural number shall be deemed to have
been made, respectively, in the plural or singular number as well; (iii) to any
section, subsection, paragraph or subparagraph shall, unless therein expressly
indicated to the contrary, be deemed to have been made to such section,
subsection, paragraph or subparagraph of this Guaranty; and (iv) to the
Guarantor, the Bank, or the Borrower shall be deemed to refer to each person
hereinabove so named, and their respective heirs, personal representatives,
successors and permitted assigns.


                                        8

<PAGE>

     12.8. Exhibits and Recitals. Each writing referred to in this Guaranty as
being attached hereto as an exhibit or otherwise referred to herein or
designated in this Guaranty, whether or not as an exhibit hereto, is hereby
incorporated herein and made a part of this Guaranty. The recitals contained
above are incorporated herein and made a part of this Guaranty by this
reference.

     12.9. Severability. No determination by any court or governmental body that
any provision of this Guaranty, or any amendment hereof, is invalid or
unenforceable in any instance shall affect the validity or enforceability of (a)
any other such provisions, or (b) such provisions in any circumstance not
controlled by such determination. Each such provision shall be valid and
enforceable to the fullest extent allowed by, and shall be construed wherever
possible as being consistent with, applicable law.

     12.10. Assignment. This Guaranty shall be binding upon and shall inure to
the benefit of the parties hereto and their respective heirs, personal
representatives, successors and permitted assigns hereunder, provided however,
that Guarantor may not assign any of its obligations hereunder to any other
person without the prior written consent of Bank, which consent may be withheld
in the Bank's sole discretion.

     12.11. Complete Understanding. This Guaranty represents the complete
understanding between the parties hereto as to the subject matter hereof, and
supersedes all prior negotiations, representations, warranties, statements or
agreements, either written or oral, between or among the parties hereto as to
the same, except as the same may be included in one or more of the Guaranty
Documents.

     IN WITNESS WHEREOF, Guarantor has executed this Guaranty and delivered this
Guaranty to the Bank the day and year first above written.

                                        "Guarantor"

                                        VERASUN CHARLES CITY, LLC,
                                        a Delaware limited liability company


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        9

<PAGE>

                                   EXHIBIT "A"

                          SUBSIDIARY SECURITY AGREEMENT

                               [See the attached.]


                                       10

<PAGE>

                                   EXHIBIT "B"

                                CONTROL AGREEMENT

                               [See the attached.]


                                       11
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "K"

                         FORT DODGE SUBSIDIARY GUARANTY

                                 [See Attached]

<PAGE>
                                                                       EXHIBIT K

                               SUBSIDIARY GUARANTY

     This Subsidiary Guaranty ("Guaranty"), made this 21st day of December,
2005, by VERASUN FORT DODGE, LLC, a Delaware limited liability company
(hereinafter referred to as "Guarantor"), whose mailing address is 100 22nd
Avenue, Brookings, South Dakota 57006, for the benefit of FIRST NATIONAL BANK OF
OMAHA, a national banking association (hereinafter referred to as the "Bank"),
whose mailing address is 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197.

                                    RECITALS

     WHEREAS, Guarantor is a wholly owned subsidiary of VeraSun Energy
Corporation, a South Dakota corporation (the "Borrower"); and

     WHEREAS, the Borrower has entered into a Revolving Credit Agreement with
Bank of even date herewith (as amended, restated or otherwise modified from time
to time, the "Credit Agreement") pursuant to which Borrower has undertaken
certain covenants and has executed and delivered to Bank an Operating Note of
even date herewith by the Borrower payable to the order of the Bank in the total
principal amount of Thirty Million Dollars ($30,000,000.00) the proceeds of
which may be drawn upon by the Borrower, for the purposes provided for in the
Credit Agreement, in accordance with and subject to the terms and restrictions
contained in the Credit Agreement (the "Note"); and

     WHEREAS, Bank has agreed to provide a Letter of Credit Facility, as defined
in the Credit Agreement, for the benefit of Borrower, whereby Bank, at
Borrower's request and subject to compliance with the terms and provisions of
the Credit Agreement, will issue one or more Letters of Credit, as defined in
the Credit Agreement, in an aggregate principal amount outstanding not to exceed
Ten Million and No/100ths Dollars ($10,000,000.00), on behalf of Borrower,
Guarantor, or other Subsidiaries in accordance with and subject to the terms and
provisions of the Credit Agreement; and

     WHEREAS, Section 2.09 of the Credit Agreement provides that the purposes of
the Credit Agreement include providing the Borrower and the Subsidiaries,
including the Guarantor, with access to (a) operating funds and (b) Letters of
Credit for operating purposes; and

     WHEREAS, Bank has, at Guarantor's previous request, issued letters of
credit for the benefit of certain third-party creditors of the Borrower, the
Guarantor or another Restricted Subsidiary on or prior to the date hereof (the
"Prior Letters of Credit"); and

     WHEREAS, to induce the Bank to enter into the Credit Agreement with the
Borrower and as a condition precedent to the Bank's obligations under the Credit
Agreement, Guarantor has agreed with the Bank to guarantee to the Bank the
Borrower's full and timely performance of all of its covenants, undertakings and
obligations under the provisions of the Credit Agreement, the Note, the Prior
Letters of Credit, the Letters of Credit and any other Loan Documents (as
defined in the Credit Agreement) (this Guaranty, the Credit Agreement, the Note,
the Prior

<PAGE>

Letters of Credit, the Letters of Credit and any other Loan Documents, including
any extensions, modifications, revisions, replacements or restatements thereof,
are herein collectively referred to as the "Guaranty Documents"); and

     WHEREAS, in entering into the Credit Agreement with the Borrower, the Bank
is relying upon Guarantor's agreements and undertakings, as set forth in the
provisions of this Guaranty.

     NOW, THEREFORE, for and in consideration of the Bank's agreement to enter
into the Credit Agreement with the Borrower, and for other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged,
Guarantor hereby agrees as follows:

     SECTION 1. DEFINITIONS. Capitalized terms used in this Guaranty, including
its preamble and recitals, and not otherwise defined herein, shall have the
meaning ascribed thereto in the Credit Agreement.

     SECTION 2. GUARANTY.

     2.1. Guarantor hereby unconditionally and irrevocably guarantees to the
Bank:

          2.1.1. The due and punctual payment in full (and not merely the
     collectibility) of the principal sum due under the Note and all interest
     and any and all other sums now or hereafter accruing thereon, in each case
     when due and payable, whether on any specific payment date or at the stated
     or accelerated maturity of any or all of the Obligations, or otherwise, all
     in accordance with the provisions of the Guaranty Documents; and

          2.1.2. The due and punctual payment in full (and not merely the
     collectibility) of any sums due and payable to Bank as reimbursement for
     Bank's payment of any draw request under any Letter of Credit, including
     but not limited to the Prior Letters of Credit, and all interest and any
     and all other sums now or hereafter accruing thereon, in each case when due
     and payable, all in accordance with the provisions of the Guaranty
     Documents; and

          2.1.3. The due and punctual payment in full (and not merely the
     collectibility) of each other sum or charge that at any time becomes due
     and payable in accordance with the provisions of any other Guaranty
     Documents; and

          2.1.4. The due and punctual performance (and not merely the
     enforceability) of all of the Borrower's other obligations under the
     provisions of the Guaranty Documents; and

          2.1.5. The due and punctual payment in full (and not merely the
     collectibility) of any and all loss, damages, or expenses incurred by the
     Bank and arising out of any default by the Borrower in performing any of
     its obligations under any of the Guaranty Documents.


                                        2

<PAGE>

     2.2. If the Borrower fails duly and punctually to pay any of such sum(s),
the Guarantor shall forthwith pay the same, together with interest thereon from
the date on which payment thereof by the Borrower became due at the Default Rate
of Interest, as provided in the Note with respect to the Borrower.

     SECTION 3. SECURITY. The Guarantor's obligations hereunder shall be secured
by (a) the Subsidiary Security Agreement dated the same date hereof executed and
delivered to the Bank by the Guarantor in the form attached hereto as Exhibit
"A" and incorporated herein by this reference and (b) the Control Agreement
dated the same date hereof executed and delivered to the Bank by the Guarantor
in the form attached hereto as Exhibit "B" and incorporated herein by this
reference.

     SECTION 4. CERTAIN RIGHTS OF BANK. The Bank may, in the exercise of its
sole and absolute discretion without providing notice to, or obtaining the
consent of, Guarantor, and without in any way releasing, altering, or impairing
any of Guarantor's obligations and liabilities under this Guaranty, from time to
time:

     4.1. Waive compliance with or any default occurring under, or grant any
other indulgence with respect to, any of the Guaranty Documents;

     4.2. Modify, revise, replace or otherwise supplement any of the provisions
of the Guaranty Documents other than this Guaranty;

     4.3. Grant any extension or renewal of or with respect to any of the
Guaranty Documents, and/or effect any release, compromise, or settlement in
connection therewith;

     4.4. Advance any sum if the Bank deems it necessary or advisable in its
reasonable credit judgment to perform any term or covenant, or satisfy any
condition, set forth in the provisions of any of the Guaranty Documents;

     4.5. Assign or otherwise transfer all or any portion of any of the Guaranty
Documents or any interest of the Bank therein and Guarantor agrees not to assert
against any such assignee or assignee's assigns, any defense, set-off,
recoupment claim or counterclaim which Guarantor has or may at any time have
against Bank for any reason whatsoever, except for payment of the Obligations.
Guarantor agrees that if Guarantor receives written notice of an assignment from
Bank, Guarantor will pay all amounts payable under this Guaranty to such
assignee or as instructed by Bank. Guarantor also agrees to confirm in writing
receipt of the notice of assignment as may be reasonably requested by Bank or
assignee;

     4.6. Deal in all respects with the Borrower as if this Guaranty were not in
effect; and

     4.7. Agree to the substitution, sale, transfer, exchange, release or other
disposition of any or all of the Collateral or any of the Guaranty Documents.


                                        3

<PAGE>

     SECTION 5. LIABILITY OF GUARANTOR.

     5.1. Guarantor's liability under the provisions of this Guaranty (a) shall
be primary, direct, unconditional, irrevocable and immediate, and (b) shall not
be conditioned or contingent upon the Bank's pursuit of any remedy that it has,
or may have, against the Borrower or any other person with respect to any of the
Guaranty Documents, pursuant to the provisions thereof or at law or in equity,
or of the adequacy of any consideration or security given therefore or in
connection therewith, or of any other circumstance that might otherwise
constitute a legal or equitable discharge of a surety or a guarantor under
applicable law. To the extent permitted by applicable law, Guarantor hereby
waives any and all defenses at law or in equity that may be available to such
Guarantor by virtue of any such circumstance.

     5.2. Without limiting the generality of the foregoing provisions of this
Section 5, the Bank shall not be required (a) to make any demand of the Borrower
or any other person, or (b) otherwise to pursue or exhaust its remedies against
the Borrower or any other person or against any or all of the Collateral
(including any other property by which the Obligations may hereafter in any
manner be secured), before, simultaneously with, or after enforcing any of the
Bank's rights and remedies under this Guaranty against Guarantor. Any one or
more successive and/or concurrent actions may be brought hereon against
Guarantor, either as part of any action brought against the Borrower, or in one
or more separate actions, as often as the Bank deems advisable in the exercise
of its sole and absolute discretion.

     5.3. Guarantor's liability under the provisions of this Guaranty shall
continue after any assignment or transfer by the Borrower or the Bank of any of
its rights under any of the Guaranty Documents or in the Collateral.

     SECTION 6. GUARANTOR'S REPRESENTATIONS, WARRANTIES AND COVENANTS. Guarantor
hereby represents, warrants, and covenants to the Bank as follows,

          6.1.1. The Guarantor is duly authorized to (a) execute and deliver
     this Guaranty and each of the Guaranty Documents executed or to be executed
     by the Guarantor, (b) perform the covenants herein and therein contained,
     (c) consummate the transactions contemplated hereby and thereby; and all
     required actions in respect to the foregoing have been taken;

          6.1.2. The execution, delivery, and performance of this Guaranty will
     not (a) violate any provision of any law, rule, regulation (including,
     without limitation, Regulations U and X of the Board of Governors of the
     Federal Reserve System), order, writ, judgment, injunction, decree,
     determination, or award presently in effect having applicability to
     Guarantor; (b) result in a breach of or constitute a default under any
     indenture or loan or credit agreement or any other material agreement,
     lease, or instrument to which Guarantor is a party or by which Guarantor or
     Guarantor's properties may be bound or affected; or (c) result in, or
     require, the creation or imposition of any encumbrance, upon or with
     respect to any of the properties now owned or hereafter acquired by
     Guarantor (except in favor of the Bank);


                                        4

<PAGE>

          6.1.3. This Guaranty, and each of the Guaranty Documents executed by
     the Guarantor, is the legal, valid, and binding obligation of the
     Guarantor, and enforceable against the Guarantor in accordance with the
     terms hereof and thereof except to the extent that such enforcement may be
     limited by applicable bankruptcy, insolvency, and other similar laws
     affecting creditors' rights generally;

          6.1.4. No information, exhibit, or report furnished by the Guarantor
     in connection with the negotiation of any of the Guaranty Documents
     contained any material misstatement of fact or omitted to state a material
     fact necessary to make the statement contained therein not materially
     misleading;

          6.1.5. There is no pending or, to the Guarantor's knowledge,
     threatened action or proceeding against or affecting the Guarantor before
     any court, governmental agency, or arbitrator which may, in any one case or
     in the aggregate, materially adversely affect the financial condition,
     operations, properties, or business of the Guarantor or the ability of the
     Guarantor to perform its obligation under the Guaranty Documents to which
     it is a party; and

          6.1.6. The Guarantor is not in default in any material respect with
     respect to any judgment, writ, injunction, decree, rule, or regulation of
     any court, arbitrator, or federal, state, municipal, or other governmental
     authority, commission, board, bureau, agency or instrumentality, domestic
     or foreign, applicable to, or with jurisdiction over, Guarantor.

     SECTION 7. WAIVERS.

     7.1. Guarantor hereby expressly waives, to the fullest extent permitted
under applicable law:

          7.1.1. Presentment and demand for payment of any sum(s) payable under
     the provisions of the Guaranty Documents and all extensions, modifications,
     revisions, replacements and restatements thereof, and protest of any
     nonpayment thereof;

          7.1.2. Notice of acceptance of this Guaranty and of such presentment,
     demand and protest;

          7.1.3. Notice of any default under this Guaranty or under the
     provisions of any of the Guaranty Documents and all extensions,
     modifications, revisions, replacements and restatements thereof, and of any
     indulgence with respect thereto;

          7.1.4. Demand for observance or performance, and enforcement, of any
     of the terms or conditions of this Guaranty, and/or any of the other
     Guaranty Documents and all extensions, modifications, revisions,
     replacements and restatements thereof;


                                        5

<PAGE>

          7.1.5. Any and all other notices and demands that may otherwise be
     required by law to be given or made; and

          7.1.6. ANY AND ALL RIGHTS THAT SUCH GUARANTOR MAY HAVE TO A TRIAL BY
     JURY IN ANY ACTION BROUGHT ON OR WITH RESPECT TO THIS GUARANTY.

     7.2. Guarantor hereby expressly agrees that if this Guaranty is enforced by
suit or otherwise, or if the Bank exercises any of its rights or remedies under
the provisions of any of the Guaranty Documents upon any default by the Borrower
in performing any of its obligations thereunder, the Guarantor will reimburse
the Bank, upon demand, for any and all reasonable out-of-pocket expenses that it
incurs in connection therewith (including, by way of example rather than of
limitation, reasonable attorneys' fees and costs).

     7.3. If any payment applied by the Bank to the Obligations is thereafter
set aside, recovered, rescinded, or required to be returned for any reason
(including without limitation, the bankruptcy, insolvency, or reorganization of
the Borrower or any other person or entity) the Obligations to which such
payment was applied shall for purposes of this Guaranty be deemed to have
continued in existence, notwithstanding such application, and this Guaranty
shall be enforceable as fully as if such application had not been made.

     SECTION 8. BANKRUPTCY OR INSOLVENCY.

     8.1. Anything contained in any of the provisions of this Guaranty or any of
the other Guaranty Documents to the contrary notwithstanding, the Bank may, in
the exercise of its sole and absolute discretion, accelerate the debt evidenced
and secured by the Guaranty Documents, if any of the following events shall
occur:

          8.1.1. Guarantor (a) applies for or consents to the appointment of a
     receiver, trustee, or liquidator of Guarantor or of all or a substantial
     part of Guarantor's assets, (b) files a voluntary petition in bankruptcy,
     or admits in writing inability to pay Guarantor's debts as they come due,
     (c) makes an assignment for the benefit of creditors, (d) files a petition
     or an answer seeking a reorganization or an arrangement with creditors or
     seeking to take advantage of any insolvency law, or (e) files an answer
     admitting the material allegations of a petition filed against Guarantor in
     any bankruptcy, reorganization, or insolvency proceeding; or

          8.1.2. (a) An order, judgment or decree is entered by any court of
     competent jurisdiction adjudicating Guarantor a bankrupt or an insolvent,
     or approving a petition seeking such a reorganization, or appointing a
     receiver, trustee, or liquidator of Guarantor or of all or a substantial
     part of Guarantor's assets, or (b) there otherwise commences, with respect
     to Guarantor or any of Guarantor's assets, any proceeding under any
     bankruptcy, reorganization, arrangement, insolvency, readjustment,
     receivership, or like law or statute, and if in either case such order,
     judgment, decree or proceeding continues unstayed for a period of sixty
     (60) consecutive days.


                                        6

<PAGE>

     8.2. Nothing in the provisions of this Section 8 shall be deemed in any way
to alter or impair any right that the Bank may have under the provisions of the
Note, the Prior Letters of Credit, the Letters of Credit or any of the other
Guaranty Documents to accelerate any debt or obligation on the occurrence of any
default or other event provided therein and entitling the Bank to accelerate
such debt or obligation, whether or not relating to Guarantor.

     SECTION 9. CERTAIN RIGHTS OF GUARANTOR.

     9.1. If Guarantor advances, or at this time has advanced, any sum to the
Borrower, or if the Borrower in any other manner is, or becomes, indebted to
Guarantor, such sum and debt shall be subordinate in all respects to any and all
amounts now or hereafter due and owing to the Bank under the provisions of any
of the Guaranty Documents.

     9.2. Anything contained in any provisions of this Guaranty, the Guaranty
Documents, or applicable law to the contrary notwithstanding, the Guarantor
shall not have any right of subrogation in or to any of the Bank's rights under
the provisions of this Guaranty, the Note, the Prior Letters of Credit, the
Letters of Credit or any of the other Guaranty Documents unless and until all
amounts now or hereafter owed to the Bank as guaranteed hereunder and under the
provisions of the Note, the Prior Letters of Credit, the Letters of Credit and
all of the other Guaranty Documents (including, by way of example rather than of
limitation, the entire principal of the Obligations and any and all interest
accruing thereon, regardless of whether, at the time in question, any one or
more installments thereof are not yet due and payable under the provisions of
the Note) are paid in full.

     SECTION 10. EFFECT OF THIS GUARANTY. Guarantor hereby represents and
warrants to the Bank that such Guarantor (a) is a wholly owned subsidiary of the
Borrower; (b) will be directly and materially benefited by the Loans by
receiving or having access to, in accordance with the terms and provisions of
the Credit Agreement, additional operating funds from Borrower as a result of
such Loans; (c) will be directly and materially benefited by the Letter of
Credit Facility by receiving or having access to, in accordance with the terms
and provisions of the Credit Agreement, Letters of Credit for the Guarantor's
operations; (d) has examined, or has had an opportunity to examine, this
Guaranty, the Credit Agreement, the Note, the Prior Letters of Credit, the
Letters of Credit, the Security Agreement, the Subsidiary Security Agreement,
the Control Agreements, and each of the other Guaranty Documents; and (e) is
represented, and in the negotiations of the terms and provisions of this
Guaranty and the Guaranty Documents has been represented, by counsel of
Guarantor's own selection relating to the terms and provisions thereof.

     SECTION 11. NOTICES, ETC. All notices and other communications provided for
under this Guaranty and under the other Guaranty Documents to which the
Guarantor is a party shall be in writing (including facsimile transmissions) and
mailed or transmitted or delivered, if to the Guarantor, at its address at 100
22nd Avenue, Brookings, South Dakota 57006, Attention: Bruce Jamerson, and if to
the Bank, at its address at 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197,
Attention: Natalie E. Mason; or, as to each party, at such other address as
shall be designated by such party in a written notice to the other party
complying as to delivery with the


                                        7

<PAGE>

terms of this Section 11. Except as otherwise provided in this Agreement, all
such notices and communications shall be effective when deposited in the U.S.
mail and addressed as aforesaid, except that notices to the Bank pursuant to the
provisions of this Section 11 shall not be effective until received by the Bank.

     SECTION 12. GENERAL.

     12.1. Amendment. This Guaranty may be amended or supplemented only by an
instrument executed and delivered by Guarantor and the Bank.

     12.2. Waiver. No party hereto shall be deemed to have waived the exercise
of any right which it holds under this Guaranty, unless that waiver is made
expressly and in writing (and no delay or omission by any party hereto in
exercising any such right shall be deemed a waiver of its future exercise). No
such waiver made as to any instance involving the exercise of any such right
shall be deemed a waiver as to any other such instance, or any other such right.

     12.3. Applicable Law. This Guaranty shall be governed by, and construed in
accordance with, the laws of the State of Nebraska without giving effect to any
choice or conflict of law provision or rule (whether of the State of Nebraska or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Nebraska.

     12.4. Submission to Jurisdiction; Venue. To induce the Bank to enter into
this Guaranty, the Guarantor irrevocably agrees that, subject to the Bank's sole
and absolute election, all suits, actions or other proceedings in any way,
manner or respect, arising out of or from or related to this Guaranty, the
Credit Agreement, the Note, the Prior Letters of Credit, the Letters of Credit,
the Security Agreement, the Control Agreement, or any of the other Guaranty
Documents, shall be subject to litigation in courts having situs within
Nebraska. The Guarantor hereby consents and submits to the jurisdiction of any
local, state, or federal court located within the State of Nebraska. The
Guarantor hereby waives any rights it may have to transfer or change the venue
of any suit, action or other proceeding brought against the Guarantor by the
Bank in accordance with this Section or in connection with this Guaranty.

     12.5. Time of Essence. Time shall be of the essence of this Guaranty.

     12.6. Headings. The headings of the sections, subsections, paragraphs, and
subparagraphs of this Guaranty are provided herein, for and only for,
convenience of reference, and shall not be considered in construing their
contents.

     12.7. Construction. As used in this Guaranty, (a) the term "person" means a
natural person, a trustee, a corporation, a partnership, a limited liability
company, and any other form of legal entity; and (b) all references made (i) in
the neuter, masculine, or feminine gender shall be deemed to have been made in
all such genders; (ii) in the singular or plural number shall be deemed to have
been made, respectively, in the plural or singular number as well; (iii) to any
section, subsection, paragraph or subparagraph shall, unless therein expressly
indicated to the contrary, be deemed to have been made to such section,
subsection, paragraph or subparagraph of


                                        8

<PAGE>

this Guaranty; and (iv) to the Guarantor, the Bank, or the Borrower shall be
deemed to refer to each person hereinabove so named, and their respective heirs,
personal representatives, successors and permitted assigns.

     12.8. Exhibits and Recitals. Each writing referred to in this Guaranty as
being attached hereto as an exhibit or otherwise referred to herein or
designated in this Guaranty, whether or not as an exhibit hereto, is hereby
incorporated herein and made a part of this Guaranty. The recitals contained
above are incorporated herein and made a part of this Guaranty by this
reference.

     12.9. Severability. No determination by any court or governmental body that
any provision of this Guaranty, or any amendment hereof, is invalid or
unenforceable in any instance shall affect the validity or enforceability of (a)
any other such provisions, or (b) such provisions in any circumstance not
controlled by such determination. Each such provision shall be valid and
enforceable to the fullest extent allowed by, and shall be construed wherever
possible as being consistent with, applicable law.

     12.10. Assignment. This Guaranty shall be binding upon and shall inure to
the benefit of the parties hereto and their respective heirs, personal
representatives, successors and permitted assigns hereunder, provided however,
that Guarantor may not assign any of its obligations hereunder to any other
person without the prior written consent of Bank, which consent may be withheld
in the Bank's sole discretion.

     12.11. Complete Understanding. This Guaranty represents the complete
understanding between the parties hereto as to the subject matter hereof, and
supersedes all prior negotiations, representations, warranties, statements or
agreements, either written or oral, between or among the parties hereto as to
the same, except as the same may be included in one or more of the Guaranty
Documents.

     IN WITNESS WHEREOF, Guarantor has executed this Guaranty and delivered this
Guaranty to the Bank the day and year first above written.

                                        "Guarantor"

                                        VERASUN FORT DODGE, LLC,
                                        a Delaware limited liability company


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        9

<PAGE>

                                   EXHIBIT "A"

                          SUBSIDIARY SECURITY AGREEMENT

                               [See the attached.]


                                       10

<PAGE>

                                   EXHIBIT "B"

                                CONTROL AGREEMENT

                               [See the attached.]


                                       11
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "L"

                      AURORA SUBSIDIARY SECURITY AGREEMENT

                                 [See Attached]

<PAGE>
                                                                       EXHIBIT L

                          SUBSIDIARY SECURITY AGREEMENT

     THIS SUBSIDIARY SECURITY AGREEMENT (this "Agreement") is made as of the
21st day of December, 2005, by VERASUN AURORA CORPORATION, a South Dakota
corporation ("Guarantor"), whose mailing address is 100 22nd Avenue, Brookings,
South Dakota 57006, in favor of FIRST NATIONAL BANK OF OMAHA, a national banking
association ("Bank"), whose mailing address is 1620 Dodge Street, STOP 1050,
Omaha, Nebraska 68197, its successors and assigns.

                                    RECITALS

     WHEREAS, Guarantor is a wholly owned subsidiary of VeraSun Energy
Corporation, a South Dakota corporation (the "Borrower"); and

     WHEREAS, the Borrower and Bank have entered into a Revolving Credit
Agreement of even date herewith (as amended, restated, or otherwise modified
from time to time, the "Credit Agreement") pursuant to which Borrower has
undertaken certain covenants and has executed and delivered to Bank an Operating
Note of even date herewith by the Borrower payable to the order of the Bank in
the total principal amount of Thirty Million Dollars ($30,000,000.00) the
proceeds of which may be drawn upon by the Borrower, for the purposes provided
for in the Credit Agreement, in accordance with and subject to the terms and
restrictions contained in the Credit Agreement (the "Note"); and

     WHEREAS, Bank has agreed to provide a Letter of Credit Facility, as
provided in the Credit Agreement, for the benefit of Borrower, whereby Bank, at
Borrower's request and subject to compliance with the terms and provisions of
the Credit Agreement, will issue one or more Letters of Credit in an aggregate
principal amount outstanding not to exceed Ten Million and No/100ths Dollars
($10,000,000.00), on behalf of Borrower, Guarantor or the other Subsidiaries in
accordance with and subject to the terms and provisions of the Credit Agreement;
and

     WHEREAS, Section 2.09 of the Credit Agreement provides that the purposes of
the Credit Agreement include providing the Borrower and the Subsidiaries,
including the Guarantor, with access to (a) operating funds and (b) Letters of
Credit for operating purposes; and

     WHEREAS, Bank has, at Guarantor's previous request, issued letters of
credit for the benefit of certain third-party creditors of the Borrower, the
Guarantor or another Restricted Subsidiary on or prior to the date hereof (the
"Prior Letters of Credit"); and

     WHEREAS, to induce the Bank to enter into the Credit Agreement with the
Borrower and as a condition precedent to the Bank's obligations under the Credit
Agreement, Guarantor has executed and delivered to Bank that certain Subsidiary
Guaranty of even date herewith in the form attached hereto as Exhibit "A" and
incorporated herein by this reference (the "Guaranty") pursuant to which the
Guarantor has guaranteed to the Bank the Borrower's full and timely performance
of the Borrower's covenants, undertakings and obligations under the provisions
of the Credit Agreement, the Note, the Prior Letters of Credit, the Letters of
Credit, and any other Loan Documents, including any extensions, modifications,
revisions, replacements or restatements thereof, in accordance with


                                        1

<PAGE>

the terms of the Guaranty; and

     WHEREAS, under the Credit Agreement, it is a condition precedent to (i)
Bank's making of Loans to the Borrower, and (ii) Bank's issuance of one or more
Letters of Credit on behalf of Borrower pursuant to the Credit Agreement, that
Guarantor execute and deliver to Bank this Agreement to secure the obligations
of the Guarantor under the Guaranty; and

     WHEREAS, Guarantor has agreed to grant a Security Interest (as hereinafter
defined) in the Collateral (as hereinafter defined) to Bank to secure the
Obligations (as hereinafter defined) in accordance with the terms and conditions
set forth herein.

     NOW, THEREFORE, in consideration of the premises set forth above, and other
good and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, and intending to be legally bound, Guarantor represents, warrants,
covenants, and agrees with Bank as follows:

     1. Definitions:

          (a) For purposes of this Agreement, "Receivables" shall mean any right
to payment for goods sold or leased or for services rendered, whether or not
such right is evidenced by an Instrument or Chattel Paper and whether or not it
has been earned by performance (including, without limitation, any Account).

          (b) All capitalized terms used in this Agreement, including its
preamble and recitals, and not otherwise defined herein, shall have the meaning
ascribed to them in the Credit Agreement.

          (c) Unless otherwise defined herein or in the Credit Agreement, or the
context otherwise requires, and whether or not capitalized, terms for which
meanings are provided in the Uniform Commercial Code, as in effect from time to
time in the State of Nebraska, are used in this Agreement with such meaning.

     2. Security Interest: Guarantor hereby BARGAINS, SELLS, GRANTS, CONVEYS,
TRANSFERS, PLEDGES, HYPOTHECATES, and ASSIGNS to Bank a first priority security
interest (the "Security Interest") in any and all (a) Receivables, (b)
Inventory, (c) any cash Proceeds (including cash insurance proceeds thereof),
rents and profits of or in respect of any and all of the foregoing items listed
in 2 (a) or 2 (b) above, and (d) the Deposit Account and Securities Account
(including, but not limited to, Guarantor's accounts #110118332, 110150484,
110197777, 110197780, 110197793, 110197803, and 110197816 at the Bank,
Guarantor's account # 186000344 at First National Capital Markets, Inc., and
such Deposit Accounts and Securities Accounts the Guarantor may establish from
time to time) into which the cash Proceeds of the items listed in 2 (a), 2 (b)
or 2 (c) above are deposited, owned by Guarantor or in which Guarantor has an
interest; together with all increases, replacements, refurbishment,
improvements, additions and substitutions therefor, all after-acquired property
with respect thereto, and all products, present and future accessions and cash
and noncash proceeds of the categories described above, including contract
rights, therefrom (collectively, the "Collateral"), to secure the complete and
timely payment, performance or discharge of (i) each of the obligations and
covenants of Guarantor under this


                                        2

<PAGE>

Agreement, the Control Agreement to which it is a party, the Guaranty, and all
modifications, substitutions, extensions and renewals of each, whether absolute
or contingent, liquidated or unliquidated, existing now or arising in the future
and (ii) all present and future indebtedness and obligations of Guarantor to the
Bank whether direct, indirect, absolute, or contingent and whether arising by
promissory note, letter of credit, guaranty, overdraft, or otherwise
(individually, an "Obligation" and collectively, the "Obligations"). The
Security Interest shall be effective with respect to each item of Collateral for
so long as any Obligation remains outstanding, regardless of whether Guarantor
becomes the owner of such Collateral prior to or contemporaneously with or
subsequent to the incurring of such Obligation.

     3. Continued Attachment and Perfection: Further to insure the attachment,
perfection, and first priority of, and the ability of Bank to enforce, the
Security Interest in the Collateral, the Guarantor agrees to take any other
action reasonably requested by Bank to insure the attachment, perfection and
first priority of, and the ability of Bank to enforce, the Security Interest in
any and all of the Collateral including, without limitation, (a) executing,
delivering and, where appropriate, filing financing statements and amendments
relating thereto under the Uniform Commercial Code, to the extent, if any, that
the Guarantor's signature thereon is required therefor, (b) complying with any
provision of any statute, regulation, or treaty of the United States, or the law
of the jurisdiction in which the Collateral is located as to any Collateral if
compliance with such provision is a condition to attachment, perfection, or
priority of, or ability of Bank to enforce, the Security Interest in such
Collateral, (c) obtaining governmental and other third-party consents and
approvals, including without limitation any consent of any licensor, lessor, or
other Person obligated on the Collateral, and (d) taking all actions required by
any earlier versions of the Uniform Commercial Code or by any other law, as
applicable in any relevant Uniform Commercial Code jurisdiction, or by other law
as applicable in any foreign jurisdiction.

     4. Authorization to File Financing Statements: The Guarantor hereby
irrevocably authorizes the Bank at any time and from time to time to file in any
Uniform Commercial Code jurisdiction any initial financing statements,
amendments and continuations thereto that contain any information required by
Part 5 of Article 9 of the Uniform Commercial Code of such jurisdiction for the
sufficiency or filing office acceptance of any financing statement or amendment.
The Guarantor agrees to furnish to the Bank any information relating to the
Collateral that Bank may request.

     5. Representations and Warranties: Guarantor expressly represents and
warrants to, and covenants with Bank that, for so long as the Security Interest
shall remain in effect:

          (a) Guarantor has, or upon acquisition will have, and at all times
until disposed of in accordance with the terms hereof, will maintain, good and
marketable title to the Collateral, free and clear of any lien, pledge, security
interest, or other encumbrance except (i) the Security Interest, (ii) current
and nondelinquent taxes or taxes being contested as provided by applicable law
in good faith and by appropriate legal proceedings in a manner which, in
Guarantor's reasonable judgment, will not jeopardize the Security Interest, and
(iii) liens arising in the ordinary course of business for sums not overdue or
sums being contested in good faith and by appropriate legal proceedings in a
manner which, in Guarantor's reasonable judgment, will not jeopardize the
Security Interest, and Guarantor will warrant and defend title to and possession
of the Collateral at Guarantor's expense against all claims or demands of all
persons other than Bank.


                                        3

<PAGE>

          (b) No financing statement (or other notice of any lien, security
interest or encumbrance) covering any of the Collateral is on file with any
governmental official or authority, or has been or will be delivered by
Guarantor to any person other than Bank without the prior written consent of
Bank.

          (c) The execution and delivery of this Agreement shall not,
immediately or with the passage of time, the giving of notice, or otherwise,
constitute a breach of, or default under, any term or provision of, or trigger
the creation of a security interest in any of the Collateral (other than the
Security Interest provided herein) pursuant to, or accelerate the obligations of
Guarantor under, any contract, mortgage, deed of trust, indenture, letter of
credit, lease, license, permit, agreement or other instrument to which Guarantor
is or may become a party or by which Guarantor or the Collateral is or may be
bound or affected.

          (d) Along with this Agreement, Guarantor is delivering to Bank a
certificate signed by Guarantor and entitled "Perfection Certificate" and
attached hereto as Exhibit "B" and incorporated herein by reference (the
"Perfection Certificate"). Guarantor represents and warrants to Bank as follows:
(i) the Guarantor's exact legal name is that indicated on the Perfection
Certificate and on the signature page hereof, (ii) the Guarantor is an
organization of the type and organized in the jurisdiction set forth in the
Perfection Certificate, (iii) the Perfection Certificate accurately sets forth
Guarantor's organizational identification number or accurately states that
Guarantor has none, (iv) the Perfection Certificate accurately sets forth
Guarantor's place of business or, if more than one, its chief executive office
as well as Guarantor's mailing address, if different, and (v) all other
information set forth on the Perfection Certificate pertaining to Guarantor is
accurate and complete.

          (e) Guarantor covenants with Bank as follows: (i) without providing at
least thirty (30) days prior written notice to Bank, Guarantor will not change
its name, its place of business or, if more than one, chief executive office, or
its mailing address or organizational identification number and (ii) Guarantor
will not change its type of organization, jurisdiction of organization, or other
legal structure.

          (f) Guarantor covenants with Bank that it will maintain with
financially sound and reputable insurers insurance with respect to its
properties, business and the Collateral against such casualties and
contingencies as shall be in accordance with general practices of businesses
engaged in similar activities in similar geographic areas and in accordance with
the Guaranty and the Control Agreement to which it is a party.

          (g) Guarantor shall:

               (i) pay on a timely basis all taxes, assessments and other
federal, state or local governmental charges and penalties levied or assessed
upon or against any Collateral or upon or against the creation, perfection or
continuance of the Security Interest, provided that no such taxes, assessments,
charges or penalties need be paid if the same are being contested in good faith
by appropriate proceedings diligently instituted and conducted;


                                        4

<PAGE>

               (ii) promptly notify Bank of any material loss of or material
damage to any Collateral or any Event of Default (defined below) hereunder;

               (iii) not use or keep any Collateral, or permit it to be used or
kept, for any unlawful purpose or in violation of applicable law, or in such a
way as would limit or void any insurance maintained on any portion of the
Collateral;

               (iv) not conduct business under any name other than that given
herein, nor change or reorganize the type of entity under which it operates,
except upon written notice to the Bank within thirty (30) days prior to such
change;

               (v) not sell, assign, or transfer all or any part of the
Collateral to any Person for less than payment of full fair market value
therefor;

               (vi) perform and comply with all the terms and conditions of the
Guaranty;

               (vii) perform and comply with all the terms and conditions of any
Letter of Credit, including, but not limited to, the Prior Letters of Credit,
and each of the documents relating thereto;

               (viii) perform and comply with all the terms and conditions of
the Control Agreements to which it is a party;

               (ix) do and perform all acts and things and execute all documents
which Bank in its reasonable discretion deems necessary or appropriate to
perfect, renew, or to give notice of, the Security Interest;

               (x) notify Bank immediately of any legal process levied or filed
against any of the Collateral or Guarantor or any other event which materially
and adversely affects or may materially and adversely affect the value, use or
possession of the Collateral or any of the rights of Guarantor or Bank in
relation to any of the Collateral; and

               (xi) preserve in existence and in accordance with their
respective terms, all of its rights, franchises, licenses, material contracts,
permits and privileges necessary to its operation, and not dissolve, merge, or
consolidate into another entity or sell, lease, transfer, or otherwise dispose
of all or a substantial part of its assets, without the prior written consent of
Bank, which consent shall not be withheld unreasonably.

     6. Disposition of Collateral: So long as there is no uncured or non-waived
Event of Default hereunder, Guarantor may, in accordance with the other terms
and conditions contained herein, sell or otherwise dispose of the Collateral
when obsolete, worn out, inadequate, unserviceable or unnecessary for use in the
operation or conduct of Guarantor's business, upon (a) replacing the same or
substituting for the same with other Collateral at least equal in value to the
value of that Collateral disposed of and in such a manner so that such
replacement or substitution Collateral shall be subject to the Security Interest
and so that such Security Interest shall be first in priority, or (b)


                                        5

<PAGE>

delivering the proceeds from the disposition of such Collateral to Bank for
credit against the Obligations or deposit in an account which is subject to the
Security Interest.

     7. Miscellaneous Undertakings: Guarantor, at its sole cost and expense,
agrees to:

          (a) pay all reasonable expenses, including without limitation,
reasonable attorneys' fees and court costs to the fullest extent permitted by
Governing Law (as hereinafter defined), actually incurred by Bank in connection
with the creation, perfection, preservation, or enforcement of the Security
Interest, the defense of the Collateral, or the exercise by Bank of any of the
rights, powers or remedies granted to Bank under this Agreement, by law or
otherwise; or

          (b) reimburse Bank within ten (10) days of Bank's demand for any
reasonable expense incurred by Bank pursuant to the foregoing authorization,
together with interest thereon at a rate equal to the lesser of (i) the three
(3) month LIBOR Rate, in effect from time to time, plus six hundred (600) basis
points, or (ii) the highest non-usurious rate of interest permitted by Governing
Law, from the date that any such expense is incurred, until reimbursed.

     8. Event of Default: The failure to cure a breach of or the failure to
comply with any material covenant, agreement, warranty, representation, or
undertaking of Guarantor contained in this Agreement within ten (10) days of
receipt of notice thereof to Guarantor from Bank shall, at the option of Bank
and without further notice or demand, constitute an "Event of Default" under
this Agreement. Additionally, the occurrence of a breach or non-fulfillment of
the terms and provisions of the Note, the Prior Letters of Credit, the Letters
of Credit, the Credit Agreement, or any of the other Loan Documents, if any such
breach or non-fulfillment is not cured in accordance with the respective terms
thereof, shall constitute an "Event of Default" under this Agreement. Further,
if for any reason the Security Interest granted hereby is not a first perfected
lien on the Collateral, or any portion thereof, it shall be deemed an "Event of
Default" under this Agreement.

     9. Bank's Rights Upon Event of Default: Upon the occurrence of an Event of
Default and at any time thereafter (unless cured or waived in each instance),
Bank may, to the fullest extent permitted by and with such notice as may be
required by Governing Law (Guarantor hereby waiving any such required notice to
the fullest extent permitted by Governing Law):

          (a) enter upon any property upon which the Collateral is located and
take possession of, assemble, collect, and move any or all of the Collateral, or
render such Collateral unusable, and store any of the Collateral at locations
acceptable to Bank;

          (b) require Guarantor to assemble any or all of the Collateral and
make it available at a mutually convenient place designated by Bank so as to
permit Bank to take possession of, move, or store, such Collateral;

          (c) sell, assign, or otherwise dispose of and deliver all or any part
of the Collateral at public or private sale, for cash or on credit, to a
wholesaler, retailer or user of each type of Collateral or at public auction;

          (d) bid and become purchaser at any public sale or auction of the
Collateral;


                                        6

<PAGE>

          (e) perform any of the Obligations, and apply any Collateral or the
proceeds therefrom to the payment of the Obligations in such order, priority and
manner as Bank in its sole discretion may determine;

          (f) operate, consume, sell or dispose of any of the Collateral as Bank
deems appropriate for the purpose of partially satisfying or fully satisfying
any or all of the Obligations;

          (g) transfer to itself or any nominee any securities constituting
Collateral, receive any income thereon and hold such income as additional
Collateral or apply it to the Obligations;

          (h) make any compromise or settlement which Bank may deem desirable or
proper with respect to any of the Collateral or any controversies or disputes
relating to the Collateral, and release any of the Collateral and any persons
liable on any of the Collateral;

          (i) endorse and deliver evidences of title, and receive, enforce and
collect by legal action or otherwise all or any portion of the Collateral; and

          (j) enforce, adjust and receive payment or performance in connection
with any insurance claims, claims for breach of warranty, claims under any
letters of credit, instruments, documents of title, chattel paper or contracts
and similar matters concerning any of the Collateral.

     10. No Responsibility: Guarantor acknowledges that Bank has no
responsibility for, and does not assume any of, Guarantor's obligations or
duties under any agreement, document of title, instrument, general intangible or
other contract or obligation relating to the Collateral. Bank shall have no duty
or obligation whatsoever to make or give any presentments, demands for
performance, notices of nonperformance, notices of protest or notices of
dishonor in connection with any of the Collateral or to take any other action to
preserve, protect or defend any of the Collateral or to preserve any value or
utility of any of the Collateral, except to the extent required by Governing Law
(Guarantor hereby waiving any such required notices or actions to the fullest
extent permitted by Governing Law).

     11. No Waiver by Bank, Etc.: The Bank shall not be deemed to have waived
any of its rights upon or under the Obligations or the Collateral unless such
waiver shall be in writing and signed by the Bank. No delay or omission on the
part of the Bank in exercising any right shall operate as a waiver of such right
or any other right. A waiver on any one occasion shall not be construed as a bar
to or waiver of any right on any future occasion. All rights and remedies of the
Bank with respect to the Obligations or the Collateral, whether evidenced hereby
or by any other instrument or papers, shall be cumulative and may be exercised
singularly, alternatively, successively, or concurrently at such time or at such
times as the Bank deems expedient.

     12. Waivers by Guarantor: To the fullest extent permitted under Governing
Law, the Guarantor waives demand, notice, protest, notice of acceptance of this
Agreement, notice of Loans made, credit extended, Collateral received or
delivered, the issuance of one or more Letters of Credit or payments made
pursuant thereto or pursuant to the Prior Letters of Credit, or other action
taken in reliance hereon, and all other demands and notices of any description.
With respect to both the


                                        7

<PAGE>

Obligations and the Collateral, the Guarantor assents to any extension or
postponement of the time of payment or any other indulgence, to any
substitution, exchange, or release of or failure to perfect any security
interest in any Collateral, to the addition or release of any party or Person
primarily or secondarily liable, to the acceptance of partial payment thereon
and the settlement, compromising, or adjusting of any thereof, all in such
manner and at such time or times as the Bank may deem advisable. The Bank shall
have no duty as to the collection or protection of the Collateral or any income
thereon, nor as to the preservation of rights against prior parties, nor as to
the preservation of any rights pertaining thereto beyond the safe custody
thereof as set forth in Section 21. The Guarantor further waives any and all
other suretyship defenses available under Governing Law.

     13. Notices: All notices and other communications provided for under this
Agreement and under the other Guaranty Documents to which the Guarantor is a
party shall be in writing (including facsimile transmissions) and mailed or
transmitted or delivered, if to the Guarantor, at its address at 100 22nd
Avenue, Brookings, South Dakota 57006, Attention: Bruce Jamerson, and if to the
Bank, at its address at 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197,
Attention: Natalie E. Mason; or, as to each party, at such other address as
shall be designated by such party in a written notice to the other party
complying as to delivery with the terms of this Section 13. Except as otherwise
provided in this Agreement, all such notices and communications shall be
effective when deposited in the U.S. mail and addressed as aforesaid, except
that notices to the Bank pursuant to the provisions of this Section 13 shall not
be effective until received by the Bank.

     14. Successors and Assigns: The terms of this Agreement shall be binding
upon and inure to the benefit of the successors-in-interest and assigns of
Guarantor and Bank; provided that Guarantor may not assign its rights or
obligations under this Agreement by contract, operation of law, or otherwise
without the prior written consent of Bank, which may be withheld in Bank's sole
discretion.

     15. Time is of the Essence: Time is an essential element to the performance
of each term of this Agreement.

     16. Headings: All headings appearing in this Agreement are for convenience
of reference only and shall be disregarded in construing this Agreement.

     17. Governing Law: This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Nebraska without giving effect to any
choice or conflict of law provision or rule (whether of the State of Nebraska or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Nebraska (the "Governing Law").

     18. Miscellaneous: The rights and remedies of Bank under this Agreement are
cumulative, and no exercise of any right or remedy shall preclude the exercise
of any other right or remedy or the later exercise of the same right or remedy.
Waivers and approvals under this Agreement shall be in writing and unless
otherwise expressly stated, waivers and approvals shall apply only to the
specific circumstance addressed. Notwithstanding any other provision of this
Agreement, Bank shall not be deemed to have accepted any property other than
cash in satisfaction


                                        8

<PAGE>

of any Obligation unless Bank shall make an express written election of said
remedy under Governing Law.

     19. Amendment: This Agreement shall not be amended or modified in any way
except by a written instrument executed by Bank and Guarantor.

     20. Severability: In the event any one or more of the provisions contained
in this Agreement shall for any reason be held to be invalid, illegal or
unenforceable in any respect under Governing Law, such invalidity, illegality or
unenforceability, at the option of Bank, shall not affect any other provision of
this Agreement, but this Agreement shall be construed as if such invalid,
illegal or unenforceable provision had never been contained herein. If the
Security Interest is invalid or unenforceable as to any portion of the
Obligations or the Collateral, all payments made on the Obligations, whether
voluntary or under foreclosure or other enforcement action or procedure, shall
be applied first to the full payment of that portion of the Obligations not
secured or not fully secured by the Collateral.

     21. Bank's Duty of Care: Bank's duty of care with respect to Collateral in
its possession shall be deemed fulfilled if Bank exercises ordinary care in
physically safekeeping and preserving such Collateral or, in the case of
Collateral in the custody or possession of a bailee or other third person, Bank
exercises ordinary care in the selection of the bailee or other third person.

     22. Preservation of Rights: Bank shall not be obligated to preserve any
rights Guarantor may have against other parties, to realize on the Collateral at
all or in any particular manner or order, or to apply any cash proceeds of
Collateral in any particular order of application, except as otherwise expressly
provided herein.

     23. Jury Trial Waiver: THE GUARANTOR HEREBY WAIVES TRIAL BY JURY IN ANY
ACTION, PROCEEDING, CLAIM, OR COUNTERCLAIM, WHETHER IN CONTRACT OR TORT, AT LAW
OR IN EQUITY, ARISING OUT OF OR IN ANY WAY RELATED TO THIS AGREEMENT. NO
EMPLOYEE OF THE BANK HAS AUTHORITY TO WAIVE, CONDITION, OR MODIFY THE TERMS AND
PROVISIONS OF THIS SECTION OF THIS AGREEMENT.

     24. Submission to Jurisdiction; Venue: Guarantor submits to the
jurisdiction of any state or federal court sitting in Omaha, Nebraska, in any
action or proceeding arising out of or relating to this Agreement and agrees
that all claims in respect of the action or proceeding may be heard and
determined in any such court. Guarantor also agrees not to bring any action or
proceeding arising out of or relating to this Agreement in any other court.
Guarantor waives any defense of inconvenient forum to the maintenance of any
action or proceeding so brought and waives any bond, surety, or other security
that might be required of Bank. Guarantor agrees that a final judgment in any
action or proceeding so brought shall be conclusive and may be enforced by suit
on the judgment or in any other manner provided by law or at equity. Guarantor
hereby waives any rights it may have to transfer or change the venue of any
suit, action or other proceeding brought against Guarantor by Bank in accordance
with this Section or in connection with this Agreement.


                                        9

<PAGE>

     IN WITNESS WHEREOF, Guarantor has caused this Agreement to be executed and
delivered to Bank as of the date set forth above.

                                        "Guarantor"

                                        VERASUN AURORA CORPORATION,
                                        a South Dakota corporation


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                       10

<PAGE>

                                   EXHIBIT "A"

                               SUBSIDIARY GUARANTY

                                [To be attached.]


                                       11

<PAGE>

                                   EXHIBIT "B"

                             PERFECTION CERTIFICATE

                             Perfection Certificate
                           (UCC Financing Statements)

     The undersigned, the _______________ of VERASUN AURORA CORPORATION, a South
Dakota corporation (the "Company"), hereby certifies on behalf of the Company,
with reference to a certain Subsidiary Security Agreement dated as of the same
date hereof (Capitalized terms used herein shall have the meaning ascribed to
such terms in the Subsidiary Security Agreement) between the Company and First
National Bank of Omaha, a national banking association (the "Bank"), to the Bank
as follows:

1. NAME. The exact legal name of the Company as that name appears on its
Certificate of Organization is as follows:

     VERASUN AURORA CORPORATION

2. OTHER IDENTIFYING FACTORS.

(a) The following is the mailing address of the Company:

     VERASUN AURORA CORPORATION
     100 22ND AVENUE
     BROOKINGS, SOUTH DAKOTA 57006

(b) If different from its mailing address, the Company's place of business or,
if more than one, its chief executive office is located at the following
address:

Address: _______________________________

City: __________________________________

County: ________________________________

State: _________________________________

Zip Code: ______________________________

(c)  The following is the type of organization of the Company:

     CORPORATION


                                       12

<PAGE>

(d)  The following is the jurisdiction of the Company's organization:

     SOUTH DAKOTA

(e) The following is the Company's state issued organizational identification
number [state "None" if the state does not issue such a number]: DB044362

3. OTHER NAMES, ETC.

(a) The following is a list of all other names (including trade names or similar
appellations) used by the Company, or any other business or organization to
which the Company became the successor by merger, consolidation, acquisition,
change in form, nature or jurisdiction of organization or otherwise, now or at
any time during the past five years:

     VERASUN ENERGY CORPORATION

(b) Attached to the Agreement as Schedule 1 is the information required in
section 2 for any other business or organization to which the Company became the
successor by merger, consolidation, acquisition, change in form, nature or
jurisdiction of organization or otherwise, now or at any time during the past
five years:

4. OTHER CURRENT LOCATIONS. The following are all other locations in the United
States of America in which the Company maintains any of its Collateral or any
books or records relating to any of the Collateral consisting of accounts or
mobile goods:

Address: _______________________________

City: __________________________________

County: ________________________________

State: _________________________________

     IN WITNESS WHEREOF, the undersigned has executed this Certificate as of
this 21st day of December, 2005.

                                        VERASUN AURORA CORPORATION,
                                        A SOUTH DAKOTA CORPORATION


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                       13
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "M"

                   CHARLES CITY SUBSIDIARY SECURITY AGREEMENT

                                 [See Attached]

<PAGE>
                                                                       EXHIBIT M

                          SUBSIDIARY SECURITY AGREEMENT

     THIS SUBSIDIARY SECURITY AGREEMENT (this "Agreement") is made as of the
21st day of December, 2005, by VERASUN CHARLES CITY, LLC, a Delaware limited
liability company ("Guarantor"), whose mailing address is 100 22nd Avenue,
Brookings, South Dakota 57006, in favor of FIRST NATIONAL BANK OF OMAHA, a
national banking association ("Bank"), whose mailing address is 1620 Dodge
Street, STOP 1050, Omaha, Nebraska 68197, its successors and assigns.

                                    RECITALS

     WHEREAS, Guarantor is a wholly owned subsidiary of VeraSun Energy
Corporation, a South Dakota corporation (the "Borrower"); and

     WHEREAS, the Borrower and Bank have entered into a Revolving Credit
Agreement of even date herewith (as amended, restated, or otherwise modified
from time to time, the "Credit Agreement") pursuant to which Borrower has
undertaken certain covenants and has executed and delivered to Bank an Operating
Note of even date herewith by the Borrower payable to the order of the Bank in
the total principal amount of Thirty Million Dollars ($30,000,000.00) the
proceeds of which may be drawn upon by the Borrower, for the purposes provided
for in the Credit Agreement, in accordance with and subject to the terms and
restrictions contained in the Credit Agreement (the "Note"); and

     WHEREAS, Bank has agreed to provide a Letter of Credit Facility, as
provided in the Credit Agreement, for the benefit of Borrower, whereby Bank, at
Borrower's request and subject to compliance with the terms and provisions of
the Credit Agreement, will issue one or more Letters of Credit in an aggregate
principal amount outstanding not to exceed Ten Million and No/100ths Dollars
($10,000,000.00), on behalf of Borrower, Guarantor or the other Subsidiaries in
accordance with and subject to the terms and provisions of the Credit Agreement;
and

     WHEREAS, Section 2.09 of the Credit Agreement provides that the purposes of
the Credit Agreement include providing the Borrower and the Subsidiaries,
including the Guarantor, with access to (a) operating funds and (b) Letters of
Credit for operating purposes; and

     WHEREAS, to induce the Bank to enter into the Credit Agreement with the
Borrower and as a condition precedent to the Bank's obligations under the Credit
Agreement, Guarantor has executed and delivered to Bank that certain Subsidiary
Guaranty of even date herewith in the form attached hereto as Exhibit "A" and
incorporated herein by this reference (the "Guaranty") pursuant to which the
Guarantor has guaranteed to the Bank the Borrower's full and timely performance
of the Borrower's covenants, undertakings and obligations under the provisions
of the Credit Agreement, the Note, the Letters of Credit, and any other Loan
Documents, including any extensions, modifications, revisions, replacements or
restatements thereof, in accordance with the terms of the Guaranty; and

     WHEREAS, under the Credit Agreement, it is a condition precedent to (i)
Bank's making of Loans to the Borrower, and (ii) Bank's issuance of one or more
Letters of Credit on behalf of


                                        1

<PAGE>

Borrower pursuant to the Credit Agreement, that Guarantor execute and deliver to
Bank this Agreement to secure the obligations of the Guarantor under the
Guaranty; and

     WHEREAS, Guarantor has agreed to grant a Security Interest (as hereinafter
defined) in the Collateral (as hereinafter defined) to Bank to secure the
Obligations (as hereinafter defined) in accordance with the terms and conditions
set forth herein.

     NOW, THEREFORE, in consideration of the premises set forth above, and other
good and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, and intending to be legally bound, Guarantor represents, warrants,
covenants, and agrees with Bank as follows:

     1. Definitions:

          (a) For purposes of this Agreement, "Receivables" shall mean any right
to payment for goods sold or leased or for services rendered, whether or not
such right is evidenced by an Instrument or Chattel Paper and whether or not it
has been earned by performance (including, without limitation, any Account).

          (b) All capitalized terms used in this Agreement, including its
preamble and recitals, and not otherwise defined herein, shall have the meaning
ascribed to them in the Credit Agreement.

          (c) Unless otherwise defined herein or in the Credit Agreement, or the
context otherwise requires, and whether or not capitalized, terms for which
meanings are provided in the Uniform Commercial Code, as in effect from time to
time in the State of Nebraska, are used in this Agreement with such meaning.

     2. Security Interest: Guarantor hereby BARGAINS, SELLS, GRANTS, CONVEYS,
TRANSFERS, PLEDGES, HYPOTHECATES, and ASSIGNS to Bank a first priority security
interest (the "Security Interest") in any and all (a) Receivables, (b)
Inventory, (c) any cash Proceeds (including cash insurance proceeds thereof),
rents and profits of or in respect of any and all of the foregoing items listed
in 2 (a) or 2 (b) above, and (d) the Deposit Account and Securities Account
(including, but not limited to, Guarantor's account # 110193441 at the Bank,
Guarantor's account # to be established as required and subject hereto at First
National Capital Markets, Inc., and such Deposit Accounts and Securities
Accounts the Guarantor may establish from time to time) into which the cash
Proceeds of the items listed in 2 (a), 2 (b) or 2 (c) above are deposited, owned
by Guarantor or in which Guarantor has an interest; together with all increases,
replacements, refurbishment, improvements, additions and substitutions therefor,
all after-acquired property with respect thereto, and all products, present and
future accessions and cash and noncash proceeds of the categories described
above, including contract rights, therefrom (collectively, the "Collateral"), to
secure the complete and timely payment, performance or discharge of (i) each of
the obligations and covenants of Guarantor under this Agreement, the Control
Agreement to which it is a party, the Guaranty, and all modifications,
substitutions, extensions and renewals of each, whether absolute or contingent,
liquidated or unliquidated, existing now or arising in the future and (ii) all
present and future indebtedness and obligations of Guarantor to the Bank whether
direct, indirect, absolute, or contingent and whether arising by


                                        2

<PAGE>

promissory note, letter of credit, guaranty, overdraft, or otherwise
(individually, an "Obligation" and collectively, the "Obligations"). The
Security Interest shall be effective with respect to each item of Collateral for
so long as any Obligation remains outstanding, regardless of whether Guarantor
becomes the owner of such Collateral prior to or contemporaneously with or
subsequent to the incurring of such Obligation.

     3. Continued Attachment and Perfection: Further to insure the attachment,
perfection, and first priority of, and the ability of Bank to enforce, the
Security Interest in the Collateral, the Guarantor agrees to take any other
action reasonably requested by Bank to insure the attachment, perfection and
first priority of, and the ability of Bank to enforce, the Security Interest in
any and all of the Collateral including, without limitation, (a) executing,
delivering and, where appropriate, filing financing statements and amendments
relating thereto under the Uniform Commercial Code, to the extent, if any, that
the Guarantor's signature thereon is required therefor, (b) complying with any
provision of any statute, regulation, or treaty of the United States, or the law
of the jurisdiction in which the Collateral is located as to any Collateral if
compliance with such provision is a condition to attachment, perfection, or
priority of, or ability of Bank to enforce, the Security Interest in such
Collateral, (c) obtaining governmental and other third-party consents and
approvals, including without limitation any consent of any licensor, lessor, or
other Person obligated on the Collateral, and (d) taking all actions required by
any earlier versions of the Uniform Commercial Code or by any other law, as
applicable in any relevant Uniform Commercial Code jurisdiction, or by other law
as applicable in any foreign jurisdiction.

     4. Authorization to File Financing Statements: The Guarantor hereby
irrevocably authorizes the Bank at any time and from time to time to file in any
Uniform Commercial Code jurisdiction any initial financing statements,
amendments and continuations thereto that contain any information required by
Part 5 of Article 9 of the Uniform Commercial Code of such jurisdiction for the
sufficiency or filing office acceptance of any financing statement or amendment.
The Guarantor agrees to furnish to the Bank any information relating to the
Collateral that Bank may request.

     5. Representations and Warranties: Guarantor expressly represents and
warrants to, and covenants with Bank that, for so long as the Security Interest
shall remain in effect:

          (a) Guarantor has, or upon acquisition will have, and at all times
until disposed of in accordance with the terms hereof, will maintain, good and
marketable title to the Collateral, free and clear of any lien, pledge, security
interest, or other encumbrance except (i) the Security Interest, (ii) current
and nondelinquent taxes or taxes being contested as provided by applicable law
in good faith and by appropriate legal proceedings in a manner which, in
Guarantor's reasonable judgment, will not jeopardize the Security Interest, and
(iii) liens arising in the ordinary course of business for sums not overdue or
sums being contested in good faith and by appropriate legal proceedings in a
manner which, in Guarantor's reasonable judgment, will not jeopardize the
Security Interest, and Guarantor will warrant and defend title to and possession
of the Collateral at Guarantor's expense against all claims or demands of all
persons other than Bank.

          (b) No financing statement (or other notice of any lien, security
interest or encumbrance) covering any of the Collateral is on file with any
governmental official or authority, or


                                        3

<PAGE>

has been or will be delivered by Guarantor to any person other than Bank without
the prior written consent of Bank.

          (c) The execution and delivery of this Agreement shall not,
immediately or with the passage of time, the giving of notice, or otherwise,
constitute a breach of, or default under, any term or provision of, or trigger
the creation of a security interest in any of the Collateral (other than the
Security Interest provided herein) pursuant to, or accelerate the obligations of
Guarantor under, any contract, mortgage, deed of trust, indenture, letter of
credit, lease, license, permit, agreement or other instrument to which Guarantor
is or may become a party or by which Guarantor or the Collateral is or may be
bound or affected.

          (d) Along with this Agreement, Guarantor is delivering to Bank a
certificate signed by Guarantor and entitled "Perfection Certificate" and
attached hereto as Exhibit "B" and incorporated herein by reference (the
"Perfection Certificate"). Guarantor represents and warrants to Bank as follows:
(i) the Guarantor's exact legal name is that indicated on the Perfection
Certificate and on the signature page hereof, (ii) the Guarantor is an
organization of the type and organized in the jurisdiction set forth in the
Perfection Certificate, (iii) the Perfection Certificate accurately sets forth
Guarantor's organizational identification number or accurately states that
Guarantor has none, (iv) the Perfection Certificate accurately sets forth
Guarantor's place of business or, if more than one, its chief executive office
as well as Guarantor's mailing address, if different, and (v) all other
information set forth on the Perfection Certificate pertaining to Guarantor is
accurate and complete.

          (e) Guarantor covenants with Bank as follows: (i) without providing at
least thirty (30) days prior written notice to Bank, Guarantor will not change
its name, its place of business or, if more than one, chief executive office, or
its mailing address or organizational identification number and (ii) Guarantor
will not change its type of organization, jurisdiction of organization, or other
legal structure.

          (f) Guarantor covenants with Bank that it will maintain with
financially sound and reputable insurers insurance with respect to its
properties, business and the Collateral against such casualties and
contingencies as shall be in accordance with general practices of businesses
engaged in similar activities in similar geographic areas and in accordance with
the Guaranty and the Control Agreement to which it is a party.

          (g) Guarantor shall:

               (i) pay on a timely basis all taxes, assessments and other
federal, state or local governmental charges and penalties levied or assessed
upon or against any Collateral or upon or against the creation, perfection or
continuance of the Security Interest, provided that no such taxes, assessments,
charges or penalties need be paid if the same are being contested in good faith
by appropriate proceedings diligently instituted and conducted;

               (ii) promptly notify Bank of any material loss of or material
damage to any Collateral or any Event of Default (defined below) hereunder;


                                        4

<PAGE>

               (iii) not use or keep any Collateral, or permit it to be used or
kept, for any unlawful purpose or in violation of applicable law, or in such a
way as would limit or void any insurance maintained on any portion of the
Collateral;

               (iv) not conduct business under any name other than that given
herein, nor change or reorganize the type of entity under which it operates,
except upon written notice to the Bank within thirty (30) days prior to such
change;

               (v) not sell, assign, or transfer all or any part of the
Collateral to any Person for less than payment of full fair market value
therefor;

               (vi) perform and comply with all the terms and conditions of the
Guaranty;

               (vii) perform and comply with all the terms and conditions of any
Letter of Credit and each of the documents relating thereto;

               (viii) perform and comply with all the terms and conditions of
the Control Agreements to which it is a party;

               (ix) do and perform all acts and things and execute all documents
which Bank in its reasonable discretion deems necessary or appropriate to
perfect, renew, or to give notice of, the Security Interest;

               (x) notify Bank immediately of any legal process levied or filed
against any of the Collateral or Guarantor or any other event which materially
and adversely affects or may materially and adversely affect the value, use or
possession of the Collateral or any of the rights of Guarantor or Bank in
relation to any of the Collateral; and

               (xi) preserve in existence and in accordance with their
respective terms, all of its rights, franchises, licenses, material contracts,
permits and privileges necessary to its operation, and not dissolve, merge, or
consolidate into another entity or sell, lease, transfer, or otherwise dispose
of all or a substantial part of its assets, without the prior written consent of
Bank, which consent shall not be withheld unreasonably.

     6. Disposition of Collateral: So long as there is no uncured or non-waived
Event of Default hereunder, Guarantor may, in accordance with the other terms
and conditions contained herein, sell or otherwise dispose of the Collateral
when obsolete, worn out, inadequate, unserviceable or unnecessary for use in the
operation or conduct of Guarantor's business, upon (a) replacing the same or
substituting for the same with other Collateral at least equal in value to the
value of that Collateral disposed of and in such a manner so that such
replacement or substitution Collateral shall be subject to the Security Interest
and so that such Security Interest shall be first in priority, or (b) delivering
the proceeds from the disposition of such Collateral to Bank for credit against
the Obligations or deposit in an account which is subject to the Security
Interest.


                                        5

<PAGE>

     7. Miscellaneous Undertakings: Guarantor, at its sole cost and expense,
agrees to:

          (a) pay all reasonable expenses, including without limitation,
reasonable attorneys' fees and court costs to the fullest extent permitted by
Governing Law (as hereinafter defined), actually incurred by Bank in connection
with the creation, perfection, preservation, or enforcement of the Security
Interest, the defense of the Collateral, or the exercise by Bank of any of the
rights, powers or remedies granted to Bank under this Agreement, by law or
otherwise; or

          (b) reimburse Bank within ten (10) days of Bank's demand for any
reasonable expense incurred by Bank pursuant to the foregoing authorization,
together with interest thereon at a rate equal to the lesser of (i) the three
(3) month LIBOR Rate, in effect from time to time, plus six hundred (600) basis
points, or (ii) the highest non-usurious rate of interest permitted by Governing
Law, from the date that any such expense is incurred, until reimbursed.

     8. Event of Default: The failure to cure a breach of or the failure to
comply with any material covenant, agreement, warranty, representation, or
undertaking of Guarantor contained in this Agreement within ten (10) days of
receipt of notice thereof to Guarantor from Bank shall, at the option of Bank
and without further notice or demand, constitute an "Event of Default" under
this Agreement. Additionally, the occurrence of a breach or non-fulfillment of
the terms and provisions of the Note, the Letters of Credit, the Credit
Agreement, or any of the other Loan Documents, if any such breach or
non-fulfillment is not cured in accordance with the respective terms thereof,
shall constitute an "Event of Default" under this Agreement. Further, if for any
reason the Security Interest granted hereby is not a first perfected lien on the
Collateral, or any portion thereof, it shall be deemed an "Event of Default"
under this Agreement.

     9. Bank's Rights Upon Event of Default: Upon the occurrence of an Event of
Default and at any time thereafter (unless cured or waived in each instance),
Bank may, to the fullest extent permitted by and with such notice as may be
required by Governing Law (Guarantor hereby waiving any such required notice to
the fullest extent permitted by Governing Law):

          (a) enter upon any property upon which the Collateral is located and
take possession of, assemble, collect, and move any or all of the Collateral, or
render such Collateral unusable, and store any of the Collateral at locations
acceptable to Bank;

          (b) require Guarantor to assemble any or all of the Collateral and
make it available at a mutually convenient place designated by Bank so as to
permit Bank to take possession of, move, or store, such Collateral;

          (c) sell, assign, or otherwise dispose of and deliver all or any part
of the Collateral at public or private sale, for cash or on credit, to a
wholesaler, retailer or user of each type of Collateral or at public auction;

          (d) bid and become purchaser at any public sale or auction of the
Collateral;


                                        6

<PAGE>

          (e) perform any of the Obligations, and apply any Collateral or the
proceeds therefrom to the payment of the Obligations in such order, priority and
manner as Bank in its sole discretion may determine;

          (f) operate, consume, sell or dispose of any of the Collateral as Bank
deems appropriate for the purpose of partially satisfying or fully satisfying
any or all of the Obligations;

          (g) transfer to itself or any nominee any securities constituting
Collateral, receive any income thereon and hold such income as additional
Collateral or apply it to the Obligations;

          (h) make any compromise or settlement which Bank may deem desirable or
proper with respect to any of the Collateral or any controversies or disputes
relating to the Collateral, and release any of the Collateral and any persons
liable on any of the Collateral;

          (i) endorse and deliver evidences of title, and receive, enforce and
collect by legal action or otherwise all or any portion of the Collateral; and

          (j) enforce, adjust and receive payment or performance in connection
with any insurance claims, claims for breach of warranty, claims under any
letters of credit, instruments, documents of title, chattel paper or contracts
and similar matters concerning any of the Collateral.

     10. No Responsibility: Guarantor acknowledges that Bank has no
responsibility for, and does not assume any of, Guarantor's obligations or
duties under any agreement, document of title, instrument, general intangible or
other contract or obligation relating to the Collateral. Bank shall have no duty
or obligation whatsoever to make or give any presentments, demands for
performance, notices of nonperformance, notices of protest or notices of
dishonor in connection with any of the Collateral or to take any other action to
preserve, protect or defend any of the Collateral or to preserve any value or
utility of any of the Collateral, except to the extent required by Governing Law
(Guarantor hereby waiving any such required notices or actions to the fullest
extent permitted by Governing Law).

     11. No Waiver by Bank, Etc.: The Bank shall not be deemed to have waived
any of its rights upon or under the Obligations or the Collateral unless such
waiver shall be in writing and signed by the Bank. No delay or omission on the
part of the Bank in exercising any right shall operate as a waiver of such right
or any other right. A waiver on any one occasion shall not be construed as a bar
to or waiver of any right on any future occasion. All rights and remedies of the
Bank with respect to the Obligations or the Collateral, whether evidenced hereby
or by any other instrument or papers, shall be cumulative and may be exercised
singularly, alternatively, successively, or concurrently at such time or at such
times as the Bank deems expedient.

     12. Waivers by Guarantor: To the fullest extent permitted under Governing
Law, the Guarantor waives demand, notice, protest, notice of acceptance of this
Agreement, notice of Loans made, credit extended, Collateral received or
delivered, the issuance of one or more Letters of Credit or payments made
pursuant thereto, or other action taken in reliance hereon, and all other
demands and notices of any description. With respect to both the Obligations and
the Collateral, the Guarantor assents to any extension or postponement of the
time of payment or any other indulgence, to any


                                        7

<PAGE>

substitution, exchange, or release of or failure to perfect any security
interest in any Collateral, to the addition or release of any party or Person
primarily or secondarily liable, to the acceptance of partial payment thereon
and the settlement, compromising, or adjusting of any thereof, all in such
manner and at such time or times as the Bank may deem advisable. The Bank shall
have no duty as to the collection or protection of the Collateral or any income
thereon, nor as to the preservation of rights against prior parties, nor as to
the preservation of any rights pertaining thereto beyond the safe custody
thereof as set forth in Section 21. The Guarantor further waives any and all
other suretyship defenses available under Governing Law.

     13. Notices: All notices and other communications provided for under this
Agreement and under the other Guaranty Documents to which the Guarantor is a
party shall be in writing (including facsimile transmissions) and mailed or
transmitted or delivered, if to the Guarantor, at its address at 100 22nd
Avenue, Brookings, South Dakota 57006, Attention: Bruce Jamerson, and if to the
Bank, at its address at 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197,
Attention: Natalie E. Mason; or, as to each party, at such other address as
shall be designated by such party in a written notice to the other party
complying as to delivery with the terms of this Section 13. Except as otherwise
provided in this Agreement, all such notices and communications shall be
effective when deposited in the U.S. mail and addressed as aforesaid, except
that notices to the Bank pursuant to the provisions of this Section 13 shall not
be effective until received by the Bank.

     14. Successors and Assigns: The terms of this Agreement shall be binding
upon and inure to the benefit of the successors-in-interest and assigns of
Guarantor and Bank; provided that Guarantor may not assign its rights or
obligations under this Agreement by contract, operation of law, or otherwise
without the prior written consent of Bank, which may be withheld in Bank's sole
discretion.

     15. Time is of the Essence: Time is an essential element to the performance
of each term of this Agreement.

     16. Headings: All headings appearing in this Agreement are for convenience
of reference only and shall be disregarded in construing this Agreement.

     17. Governing Law: This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Nebraska without giving effect to any
choice or conflict of law provision or rule (whether of the State of Nebraska or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Nebraska (the "Governing Law").

     18. Miscellaneous: The rights and remedies of Bank under this Agreement are
cumulative, and no exercise of any right or remedy shall preclude the exercise
of any other right or remedy or the later exercise of the same right or remedy.
Waivers and approvals under this Agreement shall be in writing and unless
otherwise expressly stated, waivers and approvals shall apply only to the
specific circumstance addressed. Notwithstanding any other provision of this
Agreement, Bank shall not be deemed to have accepted any property other than
cash in satisfaction of any Obligation unless Bank shall make an express written
election of said remedy under Governing Law.


                                        8

<PAGE>

     19. Amendment: This Agreement shall not be amended or modified in any way
except by a written instrument executed by Bank and Guarantor.

     20. Severability: In the event any one or more of the provisions contained
in this Agreement shall for any reason be held to be invalid, illegal or
unenforceable in any respect under Governing Law, such invalidity, illegality or
unenforceability, at the option of Bank, shall not affect any other provision of
this Agreement, but this Agreement shall be construed as if such invalid,
illegal or unenforceable provision had never been contained herein. If the
Security Interest is invalid or unenforceable as to any portion of the
Obligations or the Collateral, all payments made on the Obligations, whether
voluntary or under foreclosure or other enforcement action or procedure, shall
be applied first to the full payment of that portion of the Obligations not
secured or not fully secured by the Collateral.

     21. Bank's Duty of Care: Bank's duty of care with respect to Collateral in
its possession shall be deemed fulfilled if Bank exercises ordinary care in
physically safekeeping and preserving such Collateral or, in the case of
Collateral in the custody or possession of a bailee or other third person, Bank
exercises ordinary care in the selection of the bailee or other third person.

     22. Preservation of Rights: Bank shall not be obligated to preserve any
rights Guarantor may have against other parties, to realize on the Collateral at
all or in any particular manner or order, or to apply any cash proceeds of
Collateral in any particular order of application, except as otherwise expressly
provided herein.

     23. Jury Trial Waiver: THE GUARANTOR HEREBY WAIVES TRIAL BY JURY IN ANY
ACTION, PROCEEDING, CLAIM, OR COUNTERCLAIM, WHETHER IN CONTRACT OR TORT, AT LAW
OR IN EQUITY, ARISING OUT OF OR IN ANY WAY RELATED TO THIS AGREEMENT. NO
EMPLOYEE OF THE BANK HAS AUTHORITY TO WAIVE, CONDITION, OR MODIFY THE TERMS AND
PROVISIONS OF THIS SECTION OF THIS AGREEMENT.

     24. Submission to Jurisdiction; Venue: Guarantor submits to the
jurisdiction of any state or federal court sitting in Omaha, Nebraska, in any
action or proceeding arising out of or relating to this Agreement and agrees
that all claims in respect of the action or proceeding may be heard and
determined in any such court. Guarantor also agrees not to bring any action or
proceeding arising out of or relating to this Agreement in any other court.
Guarantor waives any defense of inconvenient forum to the maintenance of any
action or proceeding so brought and waives any bond, surety, or other security
that might be required of Bank. Guarantor agrees that a final judgment in any
action or proceeding so brought shall be conclusive and may be enforced by suit
on the judgment or in any other manner provided by law or at equity. Guarantor
hereby waives any rights it may have to transfer or change the venue of any
suit, action or other proceeding brought against Guarantor by Bank in accordance
with this Section or in connection with this Agreement.


                                        9

<PAGE>

     IN WITNESS WHEREOF, Guarantor has caused this Agreement to be executed and
delivered to Bank as of the date set forth above.

                                        "Guarantor"

                                        VERASUN CHARLES CITY, LLC,
                                        a Delaware limited liability company


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                       10

<PAGE>

                                   EXHIBIT "A"

                               SUBSIDIARY GUARANTY

                                [To be attached.]


                                       11

<PAGE>

                                   EXHIBIT "B"

                             PERFECTION CERTIFICATE

                             Perfection Certificate
                           (UCC Financing Statements)

     The undersigned, the _______________ of VERASUN CHARLES CITY, LLC, a
Delaware limited liability company (the "Company"), hereby certifies on behalf
of the Company, with reference to a certain Subsidiary Security Agreement dated
as of the same date hereof (Capitalized terms used herein shall have the meaning
ascribed to such terms in the Subsidiary Security Agreement) between the Company
and First National Bank of Omaha, a national banking association (the "Bank"),
to the Bank as follows:

1. NAME. The exact legal name of the Company as that name appears on its
Certificate of Organization is as follows:

     VERASUN CHARLES CITY, LLC

2. OTHER IDENTIFYING FACTORS.

(a) The following is the mailing address of the Company:

     VERASUN CHARLES CITY, LLC
     100 22ND AVENUE
     BROOKINGS, SOUTH DAKOTA  57006

(b) If different from its mailing address, the Company's place of business or,
if more than one, its chief executive office is located at the following
address:

Address: _______________________________

City: __________________________________

County: ________________________________

State: _________________________________

Zip Code: ______________________________

(c) The following is the type of organization of the Company:

     LIMITED LIABILITY COMPANY


                                       12

<PAGE>

(d) The following is the jurisdiction of the Company's organization:

     DELAWARE

(e) The following is the Company's state issued organizational identification
number [state "None" if the state does not issue such a number]: 4036816

3. OTHER NAMES, ETC.

(a) The following is a list of all other names (including trade names or similar
appellations) used by the Company, or any other business or organization to
which the Company became the successor by merger, consolidation, acquisition,
change in form, nature or jurisdiction of organization or otherwise, now or at
any time during the past five years:

(b) Attached to the Agreement as Schedule 1 is the information required in
section 2 for any other business or organization to which the Company became the
successor by merger, consolidation, acquisition, change in form, nature or
jurisdiction of organization or otherwise, now or at any time during the past
five years:

4. OTHER CURRENT LOCATIONS. The following are all other locations in the United
States of America in which the Company maintains any of its Collateral or any
books or records relating to any of the Collateral consisting of accounts or
mobile goods:

Address: _______________________________

City: __________________________________

County: ________________________________

State: _________________________________

     IN WITNESS WHEREOF, the undersigned has executed this Certificate as of
this 21st day of December, 2005.

                                        VERASUN CHARLES CITY, LLC,
                                        A DELAWARE LIMITED LIABILITY COMPANY


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                       13
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "N"

                    FORT DODGE SUBSIDIARY SECURITY AGREEMENT

                                 [See Attached]


<PAGE>
                                                                       EXHIBIT N

                          SUBSIDIARY SECURITY AGREEMENT

     THIS SUBSIDIARY SECURITY AGREEMENT (this "Agreement") is made as of the
21st day of December, 2005, by VERASUN FORT DODGE, LLC, a Delaware limited
liability company ("Guarantor"), whose mailing address is 100 22nd Avenue,
Brookings, South Dakota 57006, in favor of FIRST NATIONAL BANK OF OMAHA, a
national banking association ("Bank"), whose mailing address is 1620 Dodge
Street, STOP 1050, Omaha, Nebraska 68197, its successors and assigns.

                                    RECITALS

     WHEREAS, Guarantor is a wholly owned subsidiary of VeraSun Energy
Corporation, a South Dakota corporation (the "Borrower"); and

     WHEREAS, the Borrower and Bank have entered into a Revolving Credit
Agreement of even date herewith (as amended, restated, or otherwise modified
from time to time, the "Credit Agreement") pursuant to which Borrower has
undertaken certain covenants and has executed and delivered to Bank an Operating
Note of even date herewith by the Borrower payable to the order of the Bank in
the total principal amount of Thirty Million Dollars ($30,000,000.00) the
proceeds of which may be drawn upon by the Borrower, for the purposes provided
for in the Credit Agreement, in accordance with and subject to the terms and
restrictions contained in the Credit Agreement (the "Note"); and

     WHEREAS, Bank has agreed to provide a Letter of Credit Facility, as
provided in the Credit Agreement, for the benefit of Borrower, whereby Bank, at
Borrower's request and subject to compliance with the terms and provisions of
the Credit Agreement, will issue one or more Letters of Credit in an aggregate
principal amount outstanding not to exceed Ten Million and No/100ths Dollars
($10,000,000.00), on behalf of Borrower, Guarantor or the other Subsidiaries in
accordance with and subject to the terms and provisions of the Credit Agreement;
and

     WHEREAS, Section 2.09 of the Credit Agreement provides that the purposes of
the Credit Agreement include providing the Borrower and the Subsidiaries,
including the Guarantor, with access to (a) operating funds and (b) Letters of
Credit for operating purposes; and

     WHEREAS, Bank has, at Guarantor's previous request, issued letters of
credit for the benefit of certain third-party creditors of the Borrower, the
Guarantor or another Restricted Subsidiary on or prior to the date hereof (the
"Prior Letters of Credit"); and

     WHEREAS, to induce the Bank to enter into the Credit Agreement with the
Borrower and as a condition precedent to the Bank's obligations under the Credit
Agreement, Guarantor has executed and delivered to Bank that certain Subsidiary
Guaranty of even date herewith in the form attached hereto as Exhibit "A" and
incorporated herein by this reference (the "Guaranty") pursuant to which the
Guarantor has guaranteed to the Bank the Borrower's full and timely performance
of the Borrower's covenants, undertakings and obligations under the provisions
of the Credit Agreement, the Note, the Prior Letters of Credit, the Letters of
Credit, and any other Loan Documents, including any extensions, modifications,
revisions, replacements or restatements thereof, in accordance with the terms of
the Guaranty; and


                                        1

<PAGE>

     WHEREAS, under the Credit Agreement, it is a condition precedent to (i)
Bank's making of Loans to the Borrower, and (ii) Bank's issuance of one or more
Letters of Credit on behalf of Borrower pursuant to the Credit Agreement, that
Guarantor execute and deliver to Bank this Agreement to secure the obligations
of the Guarantor under the Guaranty; and

     WHEREAS, Guarantor has agreed to grant a Security Interest (as hereinafter
defined) in the Collateral (as hereinafter defined) to Bank to secure the
Obligations (as hereinafter defined) in accordance with the terms and conditions
set forth herein.

     NOW, THEREFORE, in consideration of the premises set forth above, and other
good and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, and intending to be legally bound, Guarantor represents, warrants,
covenants, and agrees with Bank as follows:

     1. Definitions:

          (a) For purposes of this Agreement, "Receivables" shall mean any right
to payment for goods sold or leased or for services rendered, whether or not
such right is evidenced by an Instrument or Chattel Paper and whether or not it
has been earned by performance (including, without limitation, any Account).

          (b) All capitalized terms used in this Agreement, including its
preamble and recitals, and not otherwise defined herein, shall have the meaning
ascribed to them in the Credit Agreement.

          (c) Unless otherwise defined herein or in the Credit Agreement, or the
context otherwise requires, and whether or not capitalized, terms for which
meanings are provided in the Uniform Commercial Code, as in effect from time to
time in the State of Nebraska, are used in this Agreement with such meaning.

     2. Security Interest: Guarantor hereby BARGAINS, SELLS, GRANTS, CONVEYS,
TRANSFERS, PLEDGES, HYPOTHECATES, and ASSIGNS to Bank a first priority security
interest (the "Security Interest") in any and all (a) Receivables, (b)
Inventory, (c) any cash Proceeds (including cash insurance proceeds thereof),
rents and profits of or in respect of any and all of the foregoing items listed
in 2 (a) or 2 (b) above, and (d) the Deposit Account and Securities Account
(including, but not limited to, Guarantor's accounts # 10118073, 110118086,
110118099, 110118167, 110118170, 110118222, 110118235 and 10195999 at the Bank,
Guarantor's accounts # 229000032, 229000033 and 208000140 at First National
Capital Markets, Inc., and such Deposit Accounts and Securities Accounts the
Guarantor may establish from time to time) into which the cash Proceeds of the
items listed in 2 (a), 2 (b) or 2 (c) above are deposited, owned by Guarantor or
in which Guarantor has an interest; together with all increases, replacements,
refurbishment, improvements, additions and substitutions therefore, all
after-acquired property with respect thereto, and all products, present and
future accessions and cash and noncash proceeds of the categories described
above, including contract rights, therefrom (collectively, the "Collateral"), to
secure the complete and timely payment, performance or discharge of (i) each of
the obligations and covenants of Guarantor under this Agreement, the Control
Agreement to which it is a party, the Guaranty, and all modifications,
substitutions,


                                        2

<PAGE>

extensions and renewals of each, whether absolute or contingent, liquidated or
unliquidated, existing now or arising in the future and (ii) all present and
future indebtedness and obligations of Guarantor to the Bank whether direct,
indirect, absolute, or contingent and whether arising by promissory note, letter
of credit, guaranty, overdraft, or otherwise (individually, an "Obligation" and
collectively, the "Obligations"). The Security Interest shall be effective with
respect to each item of Collateral for so long as any Obligation remains
outstanding, regardless of whether Guarantor becomes the owner of such
Collateral prior to or contemporaneously with or subsequent to the incurring of
such Obligation.

     3. Continued Attachment and Perfection: Further to insure the attachment,
perfection, and first priority of, and the ability of Bank to enforce, the
Security Interest in the Collateral, the Guarantor agrees to take any other
action reasonably requested by Bank to insure the attachment, perfection and
first priority of, and the ability of Bank to enforce, the Security Interest in
any and all of the Collateral including, without limitation, (a) executing,
delivering and, where appropriate, filing financing statements and amendments
relating thereto under the Uniform Commercial Code, to the extent, if any, that
the Guarantor's signature thereon is required therefor, (b) complying with any
provision of any statute, regulation, or treaty of the United States, or the law
of the jurisdiction in which the Collateral is located as to any Collateral if
compliance with such provision is a condition to attachment, perfection, or
priority of, or ability of Bank to enforce, the Security Interest in such
Collateral, (c) obtaining governmental and other third-party consents and
approvals, including without limitation any consent of any licensor, lessor, or
other Person obligated on the Collateral, and (d) taking all actions required by
any earlier versions of the Uniform Commercial Code or by any other law, as
applicable in any relevant Uniform Commercial Code jurisdiction, or by other law
as applicable in any foreign jurisdiction.

     4. Authorization to File Financing Statements: The Guarantor hereby
irrevocably authorizes the Bank at any time and from time to time to file in any
Uniform Commercial Code jurisdiction any initial financing statements,
amendments and continuations thereto that contain any information required by
Part 5 of Article 9 of the Uniform Commercial Code of such jurisdiction for the
sufficiency or filing office acceptance of any financing statement or amendment.
The Guarantor agrees to furnish to the Bank any information relating to the
Collateral that Bank may request.

     5. Representations and Warranties: Guarantor expressly represents and
warrants to, and covenants with Bank that, for so long as the Security Interest
shall remain in effect:

          (a) Guarantor has, or upon acquisition will have, and at all times
until disposed of in accordance with the terms hereof, will maintain, good and
marketable title to the Collateral, free and clear of any lien, pledge, security
interest, or other encumbrance except (i) the Security Interest, (ii) current
and nondelinquent taxes or taxes being contested as provided by applicable law
in good faith and by appropriate legal proceedings in a manner which, in
Guarantor's reasonable judgment, will not jeopardize the Security Interest, and
(iii) liens arising in the ordinary course of business for sums not overdue or
sums being contested in good faith and by appropriate legal proceedings in a
manner which, in Guarantor's reasonable judgment, will not jeopardize the
Security Interest, and Guarantor will warrant and defend title to and possession
of the Collateral at Guarantor's expense against all claims or demands of all
persons other than Bank.


                                        3

<PAGE>

          (b) No financing statement (or other notice of any lien, security
interest or encumbrance) covering any of the Collateral is on file with any
governmental official or authority, or has been or will be delivered by
Guarantor to any person other than Bank without the prior written consent of
Bank.

          (c) The execution and delivery of this Agreement shall not,
immediately or with the passage of time, the giving of notice, or otherwise,
constitute a breach of, or default under, any term or provision of, or trigger
the creation of a security interest in any of the Collateral (other than the
Security Interest provided herein) pursuant to, or accelerate the obligations of
Guarantor under, any contract, mortgage, deed of trust, indenture, letter of
credit, lease, license, permit, agreement or other instrument to which Guarantor
is or may become a party or by which Guarantor or the Collateral is or may be
bound or affected.

          (d) Along with this Agreement, Guarantor is delivering to Bank a
certificate signed by Guarantor and entitled "Perfection Certificate" and
attached hereto as Exhibit "B" and incorporated herein by reference (the
"Perfection Certificate"). Guarantor represents and warrants to Bank as follows:
(i) the Guarantor's exact legal name is that indicated on the Perfection
Certificate and on the signature page hereof, (ii) the Guarantor is an
organization of the type and organized in the jurisdiction set forth in the
Perfection Certificate, (iii) the Perfection Certificate accurately sets forth
Guarantor's organizational identification number or accurately states that
Guarantor has none, (iv) the Perfection Certificate accurately sets forth
Guarantor's place of business or, if more than one, its chief executive office
as well as Guarantor's mailing address, if different, and (v) all other
information set forth on the Perfection Certificate pertaining to Guarantor is
accurate and complete.

          (e) Guarantor covenants with Bank as follows: (i) without providing at
least thirty (30) days prior written notice to Bank, Guarantor will not change
its name, its place of business or, if more than one, chief executive office, or
its mailing address or organizational identification number and (ii) Guarantor
will not change its type of organization, jurisdiction of organization, or other
legal structure.

          (f) Guarantor covenants with Bank that it will maintain with
financially sound and reputable insurers insurance with respect to its
properties, business and the Collateral against such casualties and
contingencies as shall be in accordance with general practices of businesses
engaged in similar activities in similar geographic areas and in accordance with
the Guaranty and the Control Agreement to which it is a party.

          (g) Guarantor shall:

               (i) pay on a timely basis all taxes, assessments and other
federal, state or local governmental charges and penalties levied or assessed
upon or against any Collateral or upon or against the creation, perfection or
continuance of the Security Interest, provided that no such taxes, assessments,
charges or penalties need be paid if the same are being contested in good faith
by appropriate proceedings diligently instituted and conducted;

               (ii) promptly notify Bank of any material loss of or material
damage to any Collateral or any Event of Default (defined below) hereunder;


                                        4

<PAGE>

               (iii) not use or keep any Collateral, or permit it to be used or
kept, for any unlawful purpose or in violation of applicable law, or in such a
way as would limit or void any insurance maintained on any portion of the
Collateral;

               (iv) not conduct business under any name other than that given
herein, nor change or reorganize the type of entity under which it operates,
except upon written notice to the Bank within thirty (30) days prior to such
change;

               (v) not sell, assign, or transfer all or any part of the
Collateral to any Person for less than payment of full fair market value
therefor;

               (vi) perform and comply with all the terms and conditions of the
Guaranty;

               (vii) perform and comply with all the terms and conditions of any
Letter of Credit, including, but not limited to, the Prior Letters of Credit,
and each of the documents relating thereto;

               (viii) perform and comply with all the terms and conditions of
the Control Agreements to which it is a party;

               (ix) do and perform all acts and things and execute all documents
which Bank in its reasonable discretion deems necessary or appropriate to
perfect, renew, or to give notice of, the Security Interest;

               (x) notify Bank immediately of any legal process levied or filed
against any of the Collateral or Guarantor or any other event which materially
and adversely affects or may materially and adversely affect the value, use or
possession of the Collateral or any of the rights of Guarantor or Bank in
relation to any of the Collateral; and

               (xi) preserve in existence and in accordance with their
respective terms, all of its rights, franchises, licenses, material contracts,
permits and privileges necessary to its operation, and not dissolve, merge, or
consolidate into another entity or sell, lease, transfer, or otherwise dispose
of all or a substantial part of its assets, without the prior written consent of
Bank, which consent shall not be withheld unreasonably.

     6. Disposition of Collateral: So long as there is no uncured or non-waived
Event of Default hereunder, Guarantor may, in accordance with the other terms
and conditions contained herein, sell or otherwise dispose of the Collateral
when obsolete, worn out, inadequate, unserviceable or unnecessary for use in the
operation or conduct of Guarantor's business, upon (a) replacing the same or
substituting for the same with other Collateral at least equal in value to the
value of that Collateral disposed of and in such a manner so that such
replacement or substitution Collateral shall be subject to the Security Interest
and so that such Security Interest shall be first in priority, or (b) delivering
the proceeds from the disposition of such Collateral to Bank for credit against
the Obligations or deposit in an account which is subject to the Security
Interest.


                                        5

<PAGE>

     7. Miscellaneous Undertakings: Guarantor, at its sole cost and expense,
agrees to:

          (a) pay all reasonable expenses, including without limitation,
reasonable attorneys' fees and court costs to the fullest extent permitted by
Governing Law (as hereinafter defined), actually incurred by Bank in connection
with the creation, perfection, preservation, or enforcement of the Security
Interest, the defense of the Collateral, or the exercise by Bank of any of the
rights, powers or remedies granted to Bank under this Agreement, by law or
otherwise; or

          (b) reimburse Bank within ten (10) days of Bank's demand for any
reasonable expense incurred by Bank pursuant to the foregoing authorization,
together with interest thereon at a rate equal to the lesser of (i) the three
(3) month LIBOR Rate, in effect from time to time, plus six hundred (600) basis
points, or (ii) the highest non-usurious rate of interest permitted by Governing
Law, from the date that any such expense is incurred, until reimbursed.

     8. Event of Default: The failure to cure a breach of or the failure to
comply with any material covenant, agreement, warranty, representation, or
undertaking of Guarantor contained in this Agreement within ten (10) days of
receipt of notice thereof to Guarantor from Bank shall, at the option of Bank
and without further notice or demand, constitute an "Event of Default" under
this Agreement. Additionally, the occurrence of a breach or non-fulfillment of
the terms and provisions of the Note, the Prior Letters of Credit, the Letters
of Credit, the Credit Agreement, or any of the other Loan Documents, if any such
breach or non-fulfillment is not cured in accordance with the respective terms
thereof, shall constitute an "Event of Default" under this Agreement. Further,
if for any reason the Security Interest granted hereby is not a first perfected
lien on the Collateral, or any portion thereof, it shall be deemed an "Event of
Default" under this Agreement.

     9. Bank's Rights Upon Event of Default: Upon the occurrence of an Event of
Default and at any time thereafter (unless cured or waived in each instance),
Bank may, to the fullest extent permitted by and with such notice as may be
required by Governing Law (Guarantor hereby waiving any such required notice to
the fullest extent permitted by Governing Law):

          (a) enter upon any property upon which the Collateral is located and
take possession of, assemble, collect, and move any or all of the Collateral, or
render such Collateral unusable, and store any of the Collateral at locations
acceptable to Bank;

          (b) require Guarantor to assemble any or all of the Collateral and
make it available at a mutually convenient place designated by Bank so as to
permit Bank to take possession of, move, or store, such Collateral;

          (c) sell, assign, or otherwise dispose of and deliver all or any part
of the Collateral at public or private sale, for cash or on credit, to a
wholesaler, retailer or user of each type of Collateral or at public auction;

          (d) bid and become purchaser at any public sale or auction of the
Collateral;

          (e) perform any of the Obligations, and apply any Collateral or the
proceeds therefrom to the payment of the Obligations in such order, priority and
manner as Bank in its sole discretion may determine;


                                        6

<PAGE>

          (f) operate, consume, sell or dispose of any of the Collateral as Bank
deems appropriate for the purpose of partially satisfying or fully satisfying
any or all of the Obligations;

          (g) transfer to itself or any nominee any securities constituting
Collateral, receive any income thereon and hold such income as additional
Collateral or apply it to the Obligations;

          (h) make any compromise or settlement which Bank may deem desirable or
proper with respect to any of the Collateral or any controversies or disputes
relating to the Collateral, and release any of the Collateral and any persons
liable on any of the Collateral;

          (i) endorse and deliver evidences of title, and receive, enforce and
collect by legal action or otherwise all or any portion of the Collateral; and

          (j) enforce, adjust and receive payment or performance in connection
with any insurance claims, claims for breach of warranty, claims under any
letters of credit, instruments, documents of title, chattel paper or contracts
and similar matters concerning any of the Collateral.

     10. No Responsibility: Guarantor acknowledges that Bank has no
responsibility for, and does not assume any of, Guarantor's obligations or
duties under any agreement, document of title, instrument, general intangible or
other contract or obligation relating to the Collateral. Bank shall have no duty
or obligation whatsoever to make or give any presentments, demands for
performance, notices of nonperformance, notices of protest or notices of
dishonor in connection with any of the Collateral or to take any other action to
preserve, protect or defend any of the Collateral or to preserve any value or
utility of any of the Collateral, except to the extent required by Governing Law
(Guarantor hereby waiving any such required notices or actions to the fullest
extent permitted by Governing Law).

     11. No Waiver by Bank, Etc.: The Bank shall not be deemed to have waived
any of its rights upon or under the Obligations or the Collateral unless such
waiver shall be in writing and signed by the Bank. No delay or omission on the
part of the Bank in exercising any right shall operate as a waiver of such right
or any other right. A waiver on any one occasion shall not be construed as a bar
to or waiver of any right on any future occasion. All rights and remedies of the
Bank with respect to the Obligations or the Collateral, whether evidenced hereby
or by any other instrument or papers, shall be cumulative and may be exercised
singularly, alternatively, successively, or concurrently at such time or at such
times as the Bank deems expedient.

     12. Waivers by Guarantor: To the fullest extent permitted under Governing
Law, the Guarantor waives demand, notice, protest, notice of acceptance of this
Agreement, notice of Loans made, credit extended, Collateral received or
delivered, the issuance of one or more Letters of Credit or payments made
pursuant thereto or pursuant to the Prior Letters of Credit, or other action
taken in reliance hereon, and all other demands and notices of any description.
With respect to both the Obligations and the Collateral, the Guarantor assents
to any extension or postponement of the time of payment or any other indulgence,
to any substitution, exchange, or release of or failure to perfect any security
interest in any Collateral, to the addition or release of any party or Person
primarily or secondarily liable, to the acceptance of partial payment thereon
and the settlement, compromising, or adjusting of any thereof, all in such
manner and at such time or times as the Bank may deem


                                        7

<PAGE>

advisable. The Bank shall have no duty as to the collection or protection of the
Collateral or any income thereon, nor as to the preservation of rights against
prior parties, nor as to the preservation of any rights pertaining thereto
beyond the safe custody thereof as set forth in Section 21. The Guarantor
further waives any and all other suretyship defenses available under Governing
Law.

     13. Notices: All notices and other communications provided for under this
Agreement and under the other Guaranty Documents to which the Guarantor is a
party shall be in writing (including facsimile transmissions) and mailed or
transmitted or delivered, if to the Guarantor, at its address at 100 22nd
Avenue, Brookings, South Dakota 57006, Attention: Bruce Jamerson, and if to the
Bank, at its address at 1620 Dodge Street, STOP 1050, Omaha, Nebraska 68197,
Attention: Natalie E. Mason; or, as to each party, at such other address as
shall be designated by such party in a written notice to the other party
complying as to delivery with the terms of this Section 13. Except as otherwise
provided in this Agreement, all such notices and communications shall be
effective when deposited in the U.S. mail and addressed as aforesaid, except
that notices to the Bank pursuant to the provisions of this Section 13 shall not
be effective until received by the Bank.

     14. Successors and Assigns: The terms of this Agreement shall be binding
upon and inure to the benefit of the successors-in-interest and assigns of
Guarantor and Bank; provided that Guarantor may not assign its rights or
obligations under this Agreement by contract, operation of law, or otherwise
without the prior written consent of Bank, which may be withheld in Bank's sole
discretion.

     15. Time is of the Essence: Time is an essential element to the performance
of each term of this Agreement.

     16. Headings: All headings appearing in this Agreement are for convenience
of reference only and shall be disregarded in construing this Agreement.

     17. Governing Law: This Agreement shall be governed by, and construed in
accordance with, the laws of the State of Nebraska without giving effect to any
choice or conflict of law provision or rule (whether of the State of Nebraska or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Nebraska (the "Governing Law").

     18. Miscellaneous: The rights and remedies of Bank under this Agreement are
cumulative, and no exercise of any right or remedy shall preclude the exercise
of any other right or remedy or the later exercise of the same right or remedy.
Waivers and approvals under this Agreement shall be in writing and unless
otherwise expressly stated, waivers and approvals shall apply only to the
specific circumstance addressed. Notwithstanding any other provision of this
Agreement, Bank shall not be deemed to have accepted any property other than
cash in satisfaction of any Obligation unless Bank shall make an express written
election of said remedy under Governing Law.

     19. Amendment: This Agreement shall not be amended or modified in any way
except by a written instrument executed by Bank and Guarantor.


                                        8

<PAGE>

     20. Severability: In the event any one or more of the provisions contained
in this Agreement shall for any reason be held to be invalid, illegal or
unenforceable in any respect under Governing Law, such invalidity, illegality or
unenforceability, at the option of Bank, shall not affect any other provision of
this Agreement, but this Agreement shall be construed as if such invalid,
illegal or unenforceable provision had never been contained herein. If the
Security Interest is invalid or unenforceable as to any portion of the
Obligations or the Collateral, all payments made on the Obligations, whether
voluntary or under foreclosure or other enforcement action or procedure, shall
be applied first to the full payment of that portion of the Obligations not
secured or not fully secured by the Collateral.

     21. Bank's Duty of Care: Bank's duty of care with respect to Collateral in
its possession shall be deemed fulfilled if Bank exercises ordinary care in
physically safekeeping and preserving such Collateral or, in the case of
Collateral in the custody or possession of a bailee or other third person, Bank
exercises ordinary care in the selection of the bailee or other third person.

     22. Preservation of Rights: Bank shall not be obligated to preserve any
rights Guarantor may have against other parties, to realize on the Collateral at
all or in any particular manner or order, or to apply any cash proceeds of
Collateral in any particular order of application, except as otherwise expressly
provided herein.

     23. Jury Trial Waiver: THE GUARANTOR HEREBY WAIVES TRIAL BY JURY IN ANY
ACTION, PROCEEDING, CLAIM, OR COUNTERCLAIM, WHETHER IN CONTRACT OR TORT, AT LAW
OR IN EQUITY, ARISING OUT OF OR IN ANY WAY RELATED TO THIS AGREEMENT. NO
EMPLOYEE OF THE BANK HAS AUTHORITY TO WAIVE, CONDITION, OR MODIFY THE TERMS AND
PROVISIONS OF THIS SECTION OF THIS AGREEMENT.

     24. Submission to Jurisdiction; Venue: Guarantor submits to the
jurisdiction of any state or federal court sitting in Omaha, Nebraska, in any
action or proceeding arising out of or relating to this Agreement and agrees
that all claims in respect of the action or proceeding may be heard and
determined in any such court. Guarantor also agrees not to bring any action or
proceeding arising out of or relating to this Agreement in any other court.
Guarantor waives any defense of inconvenient forum to the maintenance of any
action or proceeding so brought and waives any bond, surety, or other security
that might be required of Bank. Guarantor agrees that a final judgment in any
action or proceeding so brought shall be conclusive and may be enforced by suit
on the judgment or in any other manner provided by law or at equity. Guarantor
hereby waives any rights it may have to transfer or change the venue of any
suit, action or other proceeding brought against Guarantor by Bank in accordance
with this Section or in connection with this Agreement.

                      REMAINDER OF PAGE INTENTIONALLY BLANK


                                        9

<PAGE>

     IN WITNESS WHEREOF, Guarantor has caused this Agreement to be executed and
delivered to Bank as of the date set forth above.

                                        "Guarantor"

                                        VERASUN FORT DODGE, LLC,
                                        a Delaware limited liability company


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                       10

<PAGE>

                                   EXHIBIT "A"

                               SUBSIDIARY GUARANTY

                                [To be attached.]


                                       11

<PAGE>

                                   EXHIBIT "B"

                             PERFECTION CERTIFICATE

                             Perfection Certificate
                           (UCC Financing Statements)

     The undersigned, the __________ of VERASUN FORT DODGE, LLC, a Delaware
limited liability company (the "Company"), hereby certifies on behalf of the
Company, with reference to a certain Subsidiary Security Agreement dated as of
the same date hereof (Capitalized terms used herein shall have the meaning
ascribed to such terms in the Subsidiary Security Agreement) between the Company
and First National Bank of Omaha, a national banking association (the "Bank"),
to the Bank as follows:

1. NAME. The exact legal name of the Company as that name appears on its
Certificate of Organization is as follows:

     VERASUN FORT DODGE, LLC

2. OTHER IDENTIFYING FACTORS.

(a) The following is the mailing address of the Company:

     VERASUN FORT DODGE, LLC
     100 22ND AVENUE
     BROOKINGS, SOUTH DAKOTA 57006

(b) If different from its mailing address, the Company's place of business or,
if more than one, its chief executive office is located at the following
address:

Address: _______________________________

City: __________________________________

County: ________________________________

State: _________________________________

Zip Code: ______________________________

(c) The following is the type of organization of the Company:

     LIMITED LIABILITY COMPANY

(d) The following is the jurisdiction of the Company's organization:


                                       12

<PAGE>

     DELAWARE

(e) The following is the Company's state issued organizational identification
number [state "None" if the state does not issue such a number]:

     3716882

3. OTHER NAMES, ETC.

(a) The following is a list of all other names (including trade names or similar
appellations) used by the Company, or any other business or organization to
which the Company became the successor by merger, consolidation, acquisition,
change in form, nature or jurisdiction of organization or otherwise, now or at
any time during the past five years:

(b) Attached to the Agreement as Schedule 1 is the information required in
section 2 for any other business or organization to which the Company became the
successor by merger, consolidation, acquisition, change in form, nature or
jurisdiction of organization or otherwise, now or at any time during the past
five years:

4. OTHER CURRENT LOCATIONS. The following are all other locations in the United
States of America in which the Company maintains any of its Collateral or any
books or records relating to any of the Collateral consisting of accounts or
mobile goods:

Address: _______________________________

City: __________________________________

County: ________________________________

State: _________________________________

     IN WITNESS WHEREOF, the undersigned has executed this Certificate as of
this 21st day of December, 2005.

                                        VERASUN FORT DODGE, LLC,
                                        A DELAWARE LIMITED LIABILITY COMPANY


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                       13
<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "O"

                   OPINION LETTER BORROWER'S CORPORATE COUNSEL

                                 [See Attached]


<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "P"

           OPINION LETTER BORROWER'S SOUTH DAKOTA AND NEBRASKA COUNSEL

                                 [See Attached]


<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "Q"

                     OPINION LETTER BORROWER'S IOWA COUNSEL

                             [Intentionally Omitted]

<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "R"

                   OPINION LETTER BORROWER'S NEBRASKA COUNSEL

                             [Intentionally Omitted]

<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "S"

                                  SUBSIDIARIES

                                 [See Attached]

<PAGE>

                           REVOLVING CREDIT AGREEMENT

                                   EXHIBIT "T"

                       FORM OF QUARTERLY PRODUCTION REPORT

                                 [See Attached]