Lam Esen's Tome is a quest item in Diablo II that can be found in the Ruined Temple level of Act III. It is needed for the quest of the same name.
Lam Esen's Tome
The ancient sage Lam Esen studied Skatsimi magic and the effects of the Prime Evils on the mortal realm. He compiled his findings in a large tome which became known as the Black Book due to its dark contents. When the Zakarum took over the lands of the East they removed the book as they believed it to be filled with heretic influences. Though many believed the Book to be lost forever, it seems the book survived somehow. It is rumoured to lie waiting in one of the darkened temples of Kurast...
References
- Diablo II gameplay