Oblivion:Wisdom of the Ages

Quick Walkthrough
# Talk to Sir Henrik to find out where he hid the Shield of the Crusader.
# Explore Fort Bulwark, solving three puzzles to gain access to the innermost room.
# Retrieve the Shield of the Crusader.

Detailed Walkthrough
Built to Protect
At the Priory of the Nine, Sir Henrik told you that if you are faithful to the teachings of Julianos, you may be able to recover the Shield of the Crusader, which he stored at Fort Bulwark for safekeeping. Further research indicates that he and several trusted friends built the Fort for the entire purpose of keeping the Shield safe within. Through traps and puzzles, the Shield is guarded from less-than-honorable hands. 

Fort Bulwark itself is on the border of Blackwood and Black Marsh, south of Fort Teleman and north-northeast of Onyx Caverns.  A marker has been added to your map, located at the top of the "d" in Blackwood.

Enter the door to Fort Bulwark; be cautious inside for there are many booby-traps. Be prepared to encounter a lot of conjurers, who apparently also know that the Shield of the Crusader is hidden here and have torn the place apart trying to find it. Most of the fort is heavily lit with torches as well, proving quite difficult for sneaking. At times you will also discover gates and drawbridges that, at first, cannot be opened. Be sure to fully explore all passages that are open to you and keep your eyes peeled, and you will find the way forward fairly obvious. That is, until you encounter the first puzzle.

The Candles
In the northwest section of the fort you will find two important items.  First, on the table there is a ''Conjurer's Note confirming that they are unsuccessfully searching for the shield.  The note contains one important hint: "The gate to the lower levels no longer halts our progress.  Make note of the candles along the walls if you would pass through".  Second, there is a handle on the floor nearby; turn it to make the gate just around the corner raise.  Make your way down the corridor which ends at a balcony with another handle on the floor.  Turn this handle and notice the two drawbridges in front of you lower.  Backtrack down or jump off the balcony and go back up, to the drawbridges you just lowered. On the other side of the drawbridges you will discover a room with tiles on the floor in a 3x4 pattern, with a locked gate on the other side.

The clue in the note tells you how to solve this puzzle: for each row, notice which side the candle(s) are located on, and how many candles there are.  Start from the side with candles, and count across the same number of tiles as there are candles.  Step on that tile, and proceed to the next row.  Or in other words, walk over the tiles in the following order to open the door:
Left
Middle
Right
Left

Also, the correct tiles make a significantly more solid "grinding" sound.

The Guardians
You will now be in the second zone of Fort Bulwark, which has been used by the conjurers as a prison and torture area.  Their victim is Sir Thedret, who is locked in one of the prison cells.  Release him to find out that he was also searching for the Shield of the Crusader, but was ambushed upon entering and captured by the conjurers.  Despite being tortured, he has refused to tell them what he knows of the shield.  Based on another Conjurer's Note'' that you can find, it was very lucky for Sir Thedret that you showed up: within the week, the conjurers were planning to "dispose" of him, "preferably in a manner most painful".  As thanks for being freed, Sir Thedret reveals the clue that he refused to tell the conjurers: "When the eyes of guardians are upon you, Julianos will show you his favor."

Continue exploring this section of the fort and disposing of the conjurers.  Watch out for one particularly nasty set of drawbridges, which are guarded by a large number of dart traps on the ceiling.  If you watch closely you will see that the darts fall in sequence - time your passage and you will pass unharmed.  Be prepared to take a lot of damage if you just run through them.  A good speed can help in bypassing some of the traps with little or no damage by simply jumping from one catwalk to the other.  In the end you will reach a large room to the west, featuring four statues.

These are the guardians.  To solve the puzzle, you need to make it so that all four statues are facing the symbol in the center of the floor at the same time.  At the base of each statue you will find a handle; activate the handle repeatedly until the statue is facing in towards the circular floor emblem in the center (or the statue diagonally across from it). At that instant the magical flames in front of the statue of Julianos will be extinguished... and a passage is opened on the south side of the room.

Rodgar's Equipment
thumb|right|Rodgar's Equipment
The newly opened passage leads to the third zone of Fort Bulwark, which the conjurers have never been able to reach.  As a result, this zone has no enemies in it.  The main room features another puzzle.  Your journal 'helpfully' tells you "I've found some sort of puzzle or trap deep inside Fort Bulwark.  I'll need to figure out what it means in order to acquire the Shield of the Crusader".  In other words, no clues this time around.

Exploring the room reveals eight stone guardian statues around the perimeter of the room, each of which can be activated (does nothing); in front of each one is a large, empty, stone chest.  In the middle of the room is a ninth chest, with a pressure plate in front of it.  When you stand on the pressure plate, you will notice one of the eight statues light up, and an item appears, hovering in mid-air in front of it.  But if you run to try to grab the item, it cannot be taken and quickly disappears.  The final piece of the mystery is that in the ninth chest you will find a single item.  If you take the item and randomly place it in another chest, it disappears... and a new item appears in the central chest.

If you do this enough times, you will notice that each of the statues has a different item that appears in front of it.  You will also notice that the same eight items appear in the central chest.  To solve the puzzle, you need to take the items from the central chest one by one and place them in the correct chest, i.e., the one where that item appears.  When you place an item in the correct chest, the statue turns around so it is facing the center of the room.

The items that belong in each chest, facing the door you entered, and going clockwise (Start at the one o'clock position) around the room, are:
Rodgar's Book
Rodgar's Hammer
Rodgar's Skull
Rodgar's Gem
Rodgar's Stone
Rodgar's Helm
Rodgar's Goblet
Rodgar's Sword

The Shield of the Crusader
Once all eight items have been placed in the correct chests, the magical flames will extinguish, and the door at the top of the stairs will open.  The next room contains the Shield of the Crusader, on an altar along with a few other items.  Take the shield, and this quest is complete.  Also, the Priory of the Nine quest is updated with the information that you have found another artifact.  Two stone slabs will also rise on each side of the altar that lead to the same corridor, which comes out in the first zone near the Fort's entrance.

Notes
If you do not rescue Sir Thedret from his cell, he will find his own way out of Fort Bulwark and you will later be visited by him at the Priory of the Nine. Since you helped him get free by diverting the Conjurers' attention from him, he will ask you if he can become a Knight so that he can repay his debt to you.
Rodgar's equipment cannot be used as they are classified as miscellaneous items, not weapons, armor, or usable items.

Bugs
 
PC users can load another copy of the Helm into their inventory using its FormID: 01000F09
 
Loading a game before entering that level of the Fort will solve the problem.
 
To solve this problem you have to (partly) empty your inventory in chests of previous rooms; after this you will be able to find Rodgar's equipment in your inventory and complete the puzzle. When the puzzle is complete and the doors are open you can get your gear back from the containers in the previous rooms and continue the quest. 
 
Some possible workarounds:
You have a small time frame to avoid the force-greeting. Save before entering the building if you do not have autosave upon entering enabled. Lathon will likely come from the left side and have to navigate around the other Crusaders. Deviate slightly to the right and run up the stairs. As he makes his way up, jump from the highest point of the stairs, down to the table and try to find Thedret to engage in conversation. Alternatively, Thedret may be upstairs already and you can avoid having to circle around Lathon. After speaking with Sir Thedret, immediately check the basement to see if Sergius is behind the anvil.
Another possible fix is to try and enter the basement as quickly as possible by running the long way around the dining table. After waiting for a few in-game minutes, Sir Thedret should come downstairs to train upon which you may speak with him to trigger the blacksmith (who will materialize right before your eyes). 

 
Restarting/relaunching the game seems to fix this.

Journal Entries