Did you read it? Is Joseph Redpath mentioned? If he is, then perhaps we can save him!
Ah. The Annals of Darrowshire tell a very unsettling tale. It says that during the battle, Joseph Redpath was corrupted and joined the ranks of the Scourge! He then betrayed the defenders of Darrowshire.
That is an ill fate. If we can, we should try to change that fate, don't you think?
The book you are looking for is a random spawn among the book in the building. You can distinguish the real book from the trapped fakes by:
viewed from the side, the real book has pages all of one color
the pages of the fake books have two separate colors
the real book has a very faint X on the spine.
Your video settings may need to be turned up in order to spot these differences.
The real book may not be initially present. The spawns are random, and it is possible that none of the tomes in the building are the "real one". In this case, you will need to take the trapped Musty Tomes until the real book appears at one of the spawn points.