You see a forbidden tome.
It weighs 6.50 oz.
Notes
This is one of the two items required for the Forbidden Knowledge achievement.
If you have already eaten a 
Forbidden Fruit, then upon using the 
Key to Knowledge on the 
Forbidden Tome, both of which will be consumed, you will receive the following message along with the Forbidden Knowledge achievement: You gained a tremendous amount of knowledge.
Dropped By
Trade Details
Buy From
No NPC sells this item.
Sell To
No NPC buys this item.