| “ | Welcome to my reading room. (...) Dean, every notebook on this particular shelf tells a version of how you die - you specifically. | ” |
Death's Reading Room, also referred to as Death's Library, is a special library within the veil that contains notebooks, each detailing a version of how a person may die.
Layout and contents
The reading room contains many shelves of books detailing the death of an individual. Curiously there is an entire shelf dedicated to a potential death that Dean may experience. Billie told Dean that some of these books say that he may potentially die from a heart attack, being burned by a red haired witch, stabbed by a ghoul in a graveyard, and "on and on". After Dean traps Michael in his mind, all but one of these notebooks change to Michael escaping and using Dean's body to destroy the world. These books can be taken to the physical plane as seen by Billie's ability to give Dean the book containing the one different fate in the Men of Letters bunker.
Billie later reveals that even God has a book in the library which reveals how God dies. The books are not written by God or even Death but rather they write themselves. God had no choice but to write himself into the framework of the world which makes him vulnerable. No one can read their book unless Billie lets them, not even God. All Billie will reveal is that God's book contains Jack and the Winchesters.