De Vermiis Mysteriis was a book in a yellow cover that could be found within the 2nd floor library of Derceto. Reading the book kills the playing character after he/she reads it, unless the player is standing on the tile with the pentogram, which is located in the nearby ritual chamber. it is considered more dangerous than reading Fragments of the Book of Abdul. Unlike the Book of Abdul, which simply drives readers mad, reading this book unprotected causes the player to be lifted into the air, their bodies twisted and crushed by some tremendous force before being dropped back to the ground, dead, as if picked up and clenched in a monstrous invisible hand.