Lord Kertis's Journal is a tome found in Act V of Diablo III. It is dropped after completing the Lord of Fools event in Paths of the Drowned. Obtaining the journal adds to the People Finder achievement.
It reads as follows:
"I curse you, Saul! You sold me that piece of waterlogged land to build my castle on?! Well, I will have the last laugh, you dog! I will build my castle here, and it will be the grandest castle ever! Do you hear me, Saul? Ever!"