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                                                                    Exhibit 10.4



                            INFORMATION HOLDINGS INC.

                             1998 STOCK OPTION PLAN



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                                    ARTICLE I

                                     PURPOSE

     This 1998 Stock Option Plan (the "Plan") is intended to encourage stock
ownership in Information Holdings Inc. (the "Company") by employees and
directors of the Company and its subsidiaries in order to increase their
proprietary interest in the Company's success and to encourage such employees
and directors to remain in the service of the Company and its subsidiaries.


                                   ARTICLE II

                               CERTAIN DEFINITIONS

     "AFFILIATE" of an entity shall mean any person or entity controlling,
controlled by or under common control with, such entity, where "control" means
the power to exercise a controlling influence over the management or policies of
such person or entity.

     "BOARD" shall mean the Board of Directors of the Company.

     "CHANGE OF CONTROL" shall have the meaning set forth in Article XI.

     "CODE" shall mean the Internal Revenue Code of 1986, as amended.

     "COMMITTEE" shall mean (i) the Stock Option Committee of the Board which,
if and to the extent practicable, shall be comprised of at least two persons who
qualify as "non-employee directors" under Rule 16b-3 promulgated by the
Securities and Exchange Commission under the Securities Exchange Act of 1934,
and as "outside directors" under Section 162(m) of the Code or (ii) if a Stock
Option Committee has not been designated by the Board, the Board.

     "COMMON STOCK" shall mean the voting common stock of the Company, par value
$0.01 per share.

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     "ELIGIBLE EMPLOYEE" shall mean any person employed on a full-time basis by
the Company or any of its subsidiaries, or any director of the Company.

     "EXERCISE PRICE" shall have the meaning assigned to such term in Article VI
hereof.

     "ISO" shall mean an "incentive stock option" within the meaning of Section
422 of the Code.

     "NON-QUALIFIED OPTION" shall mean an Option which is not an ISO.

     "OPTION" shall mean any option granted under the Plan.

     "OPTIONEE" shall mean any holder of an Option.

     "OPTION AGREEMENT" shall mean the agreement between an Optionee and the
Company governing Options granted under the Plan, the forms of which shall be
consistent with the terms of the Plan but need not be identical.

     "WP VENTURES" shall mean Warburg, Pincus Ventures, L.P., any Affiliate
thereof, or any successor thereto.


                                   ARTICLE III

                                      STOCK

     The stock to be issued upon the exercise of Options shall be shares of
authorized but unissued Common Stock or previously issued shares of Common Stock
reacquired by the Company. The aggregate number of shares of Common Stock as to
which Options may be granted under the Plan at any time shall not exceed
866,886, subject to adjustment from time to time in accordance with the
provisions of Article X hereof.

     The number of shares of Common Stock available for grant of Options at any
time under the Plan shall be decreased by the sum of (i) the number of shares
with respect to which Options have been issued and have not lapsed or been
canceled, in each case, prior to such time and (ii) the number of shares issued
prior to such time upon exercise of Options. In the event that any outstanding
Option under the Plan lapses in accordance with Articles VII or VIII hereof,
prior to the end of the period during which Options may be granted, the shares
of Common Stock 


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subject to the unexercised portion of such Option shall again be available for
the granting of Options under the Plan.


                                   ARTICLE IV

                                  PARTICIPATION

     Optionees shall be limited to Eligible Employees who have received written
notice of their selection to participate in the Plan and who have entered into
an Option Agreement. Each Option Agreement shall state the total number of
shares of Common Stock which are subject to the Option granted. No Eligible
Employee shall at any time have a right to be selected as a participant.

                                    ARTICLE V

                                 ADMINISTRATION

     The Plan shall be administered by the Committee which shall have sole
authority, in its absolute discretion: (a) to select which Eligible Employees
shall be granted Options; (b) to determine the number of Options to be granted
to such Eligible Employees and whether such Options shall be ISOs or
Non-Qualified Options; (c) to prescribe the form or forms of the Option
Agreements under the Plan; (d) to adopt, amend or rescind such rules and
regulations as, in its opinion, may be advisable for the administration of the
Plan; and (e) to construe and interpret the Plan, and all such rules and
regulations, and to make all other determinations deemed necessary or advisable
for the administration of the Plan. All decisions, determinations and
interpretations of the Committee made in good faith shall be final and binding
on all participants. Neither the Committee nor any member of the Committee shall
be liable for any act, omission, interpretation, construction or determination
made in connection with the Plan in good faith, and the members of the Committee
shall be entitled to indemnification and reimbursement by the Company in respect
of any claim, loss, damage or expense (including, without limitation, counsel
fees) arising therefrom to the full extent permitted by Delaware law and under
any directors' and officers' liability insurance coverage which may be in effect
from time to time.


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                                   ARTICLE VI

                                 EXERCISE PRICE

     The Exercise Price per share of Common Stock covered by Options granted
under the Plan shall be established on or prior to the date of grant by the
Committee and shall be set forth in the Optionee's Option Agreement. Payment
shall be made in full upon exercise of the Option by delivering to the Company
at its principal executive offices cash or a certified check, bank draft or
money order payable to the order of the Company in the aggregate amount of the
Exercise Price, or in accordance with any cashless exercise procedures adopted
by the Committee from time to time.

                                   ARTICLE VII

                               VESTING OF OPTIONS

     All Options granted under the Plan shall vest and become exercisable in
accordance with Article XI hereof and vesting schedules established by the
Committee at the time of grant.


                                  ARTICLE VIII

                            TERMINATION OF EMPLOYMENT

     Each Option will have a ten-year term from the date of grant, subject to
earlier termination upon termination of the Optionee's employment, as determined
by the Committee.


                                   ARTICLE IX

                                 TRANSFERABILITY

     Options shall not be transferable, except by will or the laws of descent
and distribution. During the lifetime of the Optionee, Options shall be
exercisable only by the Optionee.


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                                    ARTICLE X

                  ADJUSTMENT FOR RECAPITALIZATION, MERGER, ETC.

     The aggregate number of shares of Common Stock which may be purchased
pursuant to Options granted hereunder, the maximum number of shares of Stock
with respect to which Options may be granted to any single Optionee during any
calendar year, the number of shares of Common Stock covered by each outstanding
Option and the price per share thereof shall be appropriately adjusted for any
increase or decrease in the number of outstanding shares of Common Stock
resulting from a stock split or other subdivision or consolidation of shares of
Common Stock, or for other capital adjustments or payments of stock dividends or
distributions or other increases or decreases in the outstanding shares of
Common Stock effected without receipt of consideration by the Company.

     If the Company shall be sold, reorganized, consolidated, or merged with
another corporation, or if all or substantially all of the assets of the Company
shall be sold or exchanged (a "Corporate Event"), (i) each Optionee shall, at
the time of such Corporate Event, be entitled to receive upon the exercise of
his Option the same number and kind of shares of common stock or the same amount
of property, cash or other securities as he would have been entitled to receive
upon the occurrence of such Corporate Event as if he had been, immediately prior
to such event or on the record date relating to such event, the holder of the
number of shares of Common Stock covered by his Option, and (ii) if the Company
is not the surviving corporation in such Corporate Event, the Company shall
require the successor corporation or parent thereof to assume such outstanding
Options; PROVIDED, HOWEVER, that the Committee may, in its discretion and in
lieu of requiring such assumption, provide that all outstanding Options shall
terminate as of the consummation of such Corporate Event and accelerate the
exercisability of all outstanding Options to any date prior to the date of such
Corporate Event.

     The foregoing adjustments and the manner of application of the foregoing
provisions shall be determined by the Committee in its sole discretion. Any such
adjustment may provide for the elimination of any fractional share which might
otherwise become subject to an Option.


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                                   ARTICLE XI

                                CHANGE OF CONTROL

     In the event of a Change of Control, each outstanding Option under the Plan
shall vest and become immediately exercisable in full as of the date immediately
preceding the date of such Change of Control, or such other date, not later than
the date of such Change of Control, as shall be established by the Committee in
its discretion.

     For purposes of the Plan, a "Change of Control" shall mean:

     (a) The acquisition by any individual, entity or group (within the meaning
of Section 13(d)(3) or 14(d)(2) of the Securities Exchange Act of 1934, as
amended (the "Exchange Act")) (a "Person") of beneficial ownership (within the
meaning of Rule 13d-3 promulgated under the Exchange Act) of 50% or more of
either (i) the then outstanding shares of Common Stock (the "Outstanding Company
Stock") or (ii) the combined voting power of the then outstanding voting
securities of the Company entitled to vote generally in the election of
directors (the "Outstanding Company Voting Securities"); provided, however, that
for purposes of this subsection (a), the following acquisitions shall not
constitute a Change of Control: (i) any acquisition directly from the Company,
(ii) any acquisition by the Company, (iii) any acquisition by any employee
benefit plan (or related trust) sponsored or maintained by the Company, (iv) any
acquisition by WP Ventures, or (v) any acquisition by any corporation pursuant
to a transaction which complies with clauses (i), (ii), and (iii) of subsection
(c) of this ARTICLE XI;

     (b) Individuals who, as of the date hereof, constitute the Board (the
"Incumbent Board") cease for any reason to constitute at least a majority of the
Board; provided, however, that any individual becoming a director subsequent to
the effective date of the Plan whose election, or nomination for election by the
Company's stockholders, was approved by a vote of at least a majority of the
directors then comprising the Incumbent Board shall be considered as though such
individual were a member of the Incumbent Board, but excluding, for this
purpose, any such individual whose initial assumption of office occurs as a
result of an actual or threatened election contest with respect to the election
or removal of directors or other actual or threatened solicitation of proxies or
consents by or on behalf of a Person other than the Board; or

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     (c) Consummation of a Corporate Event, unless, following such Corporate
Event, (i) all or substantially all of the individuals and entities who were the
beneficial owners, respectively, of the Outstanding Company Stock and
Outstanding Company Voting Securities immediately prior to such Corporate Event
beneficially own, directly or indirectly, more than 50% of, respectively, the
then outstanding shares of common stock and the combined voting power of the
then outstanding voting securities entitled to vote generally in the election of
directors of the corporation resulting from such Corporate Event (including,
without limitation, a corporation which as a result of such transaction owns the
Company or all or substantially all of the Company's assets either directly or
through one or more subsidiaries) upon consummation of such Corporate Event in
substantially the same proportions as their ownership, immediately prior to such
Corporate Event, of the Outstanding Company Stock and Outstanding Company Voting
Securities, as the case may be, (ii) no Person other than (1) WP Ventures, (2)
any corporation resulting from such Corporate Event, or (3) any employee benefit
plan (or related trust) of the Company or such corporation resulting from such
Corporate Event, beneficially owns, directly or indirectly, 50% or more of,
respectively, the then outstanding shares of common stock of the corporation
resulting from such Corporate Event or the combined voting power of the then
outstanding voting securities of such corporation except to the extent that such
ownership existed prior to the Corporate Event, and (iii) at least a majority of
the members of the board of directors of the corporation resulting from such
Corporate Event were members of the Incumbent Board at the time of the execution
of the initial agreement, or of the action of the Board, providing for such
Corporate Event; or

     (d) Approval by the stockholders of the Company of a complete liquidation
or dissolution of the Company.


                                   ARTICLE XII

                             RIGHTS AS A STOCKHOLDER

     An Optionee or a transferee of an Option shall have no rights as a
stockholder with respect to any shares covered by his Option until he shall have
become the holder of record of such shares, and he shall not be entitled to any
dividends or distributions or other rights in respect of such shares for which
the record date is prior to the date on which he shall have become the holder of
record thereof.


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                                  ARTICLE XIII

                                EMPLOYMENT RIGHTS

     Nothing in the Plan or in any Option Agreement entered into hereunder shall
confer on any Optionee who is an employee of the Company or any of its
subsidiaries any right to continue in the employ of the Company or any of its
subsidiaries or to interfere in any way with the right of the Company or any of
its subsidiaries to terminate the Optionee's employment at any time.


                                   ARTICLE XIV

                              TRANSFER RESTRICTIONS

     Appropriate legends shall be placed on the stock certificates evidencing
shares issued upon exercise of Options to reflect any relevant transfer
restrictions.


                                   ARTICLE XV

                       AMENDMENT OR DISCONTINUANCE OF PLAN

     The Board may from time to time, to the extent permitted by applicable law,
amend, suspend, or discontinue the Plan; provided, however, that the Board may
not take any action which would have a material adverse effect on outstanding
Options or any unexercised rights under outstanding Options without the consent
of the Optionee whose options would be adversely affected thereby.


                                   ARTICLE XVI

                             CANCELLATION OF OPTIONS

     The Committee, in its discretion, may, with the express written consent of
the Optionee to be affected, cancel any Option held by such consenting Optionee
hereunder.


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                                  ARTICLE XVII

                                  MISCELLANEOUS

     (a) The Company may, in its discretion, require that an Optionee pay to the
Company, at the time of exercise, such amount as the Company deems necessary
under law to satisfy its obligations to withhold Federal, state, or local income
or other taxes incurred by reason of the exercise or the transfer of shares
thereupon.

     (b) Anything in the Plan or any Option Agreement entered into pursuant to
the Plan to the contrary notwithstanding, if, at any time specified herein or
therein for the making of any issue of shares of Common Stock, any law,
regulation or requirement of any governmental authority having jurisdiction in
the premises shall require either the Company or the Optionee (or the Optionee's
personal legal representative or transferee) to take any action in connection
with any such shares to be issued, the issue of such shares shall be deferred
until such action shall have been taken, provided, however, that the Company
shall not be required to take such action.

     (c) The Plan shall be governed by and construed in accordance with the laws
of the State of Delaware without reference to the principles of conflicts of law
thereof.

     (d) No provision of the Plan shall require the Company, for the purpose of
satisfying any obligations under the Plan, to purchase assets or place any
assets in a trust or other entity to which contributions are made or otherwise
to segregate any assets, nor shall the Company maintain separate bank accounts,
books, records or other evidence of the existence of a segregated or separately
maintained or administered fund for such purposes.

     (e) Except as otherwise specifically provided in the relevant plan
document, no payment under the Plan or other amount required to be reported as
income for Federal income tax purposes shall be taken into account in
determining any benefits under any pension, retirement, profit sharing, group
insurance or other benefit plan of the Company.

     (f) The expenses of administering the Plan shall be borne by the Company.
The proceeds received by the Company from 


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the exercise of any Options pursuant to the Plan will be used for general
corporate purposes.

     (g) Masculine pronouns and other words of masculine gender shall refer to
both men and women.

     (h) The titles and headings of the sections in the Plan are for convenience
of reference only, and in the event of any conflict, the text of the Plan,
rather than such titles or headings, shall control.


                                  ARTICLE XVIII

                           SPECIAL PROVISIONS FOR ISOS

     (a) ISOs must be granted within ten years from the date the Plan is
adopted, or the date the Plan is approved by the stockholders of the Company,
whichever is earlier.

     (b) ISOs may not be exercised after the expiration of ten years from the
date such ISOs are granted.

     (c) The Exercise Price of ISOs may not be less than the fair market value
of a share of Common Stock at the time such ISOs are granted, as determined by
the Committee. In such case, fair market value shall be determined in a manner
consistent with the rules and regulations under Section 422 of the Code.

     (d) ISOs may not be granted to a person who owns stock possessing more than
10% of the total combined voting power of all classes of stock of the Company or
any "subsidiary corporation" of the Company within the meaning of Section 424(f)
of the Code.

     (e) To the extent the aggregate fair market value of the Common Stock with
respect to which ISOs are exercisable for the first time by any Optionee during
a calendar year (under all plans of the Company and all "subsidiary
corporations" of the Company within the meaning of Section 424(f) of the Code)
exceeds $100,000, such ISOs shall be treated as Non-Qualified Options. For
purposes of the preceding sentence, the fair market value of the Common Stock
shall be determined by the Committee at the time the ISO covering such stock is
granted.

     (f) No ISOs may be granted under the Plan unless the Plan has been approved
by the stockholders of the Company within 


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12 months before or after the date of the Plan's adoption by the Board.

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