The Fuller Memorandum (Laundry Files Series #3)

Computational demonologist Bob Howard is catching up on his filing in the Laundry archives when a top secret dossier known as the Fuller Memorandum vanishes-along with his boss, who is suspected of stealing the file. And while dealing with Russian agents, ancient demons, and a maniacal death cult, Bob must find the missing memorandum before the world ends up disappearing next.