I've slowly been building up my Calibre library and the book ID numbers have been creeping up too.
Purely coincidentally, after importing my latest batch of books, I realized that book #666 was
Good Omens by Terry Pratchett and Neil Gaiman. The book is a comedy about the End Times and the birth of the Son of Satan.
The cover illustration is the number 666.
Someone's trying to tell me something...
