The archangel Michael is missing. His brother Gabriel enlists BA, the Bad Angel, to find him. BA is told if he completes the mission, he’d no longer have to guard Purgatory, which was his punishment for committing centuries of mistakes. Michael’s blood is being used in a drug by a powerful being, known as the Peddler, that makes humans homicidal. The purpose of the drug is to wipeout humanity. Because the Peddler is using vampires and rogue demons to do is bidding, Jericho Caine, the vampire slayer, Father Tom Padilla, the demon hunter, and Alexander Merryweather, The Grand Librarian and wizard, also join the fray.
The drug also draws the attention of the demon lord Hangoctuforre, who wants to conquer the Earth for himself. He raises his pupil, Damian Red, a sorcerer, and also aligns himself with a fallen angel to stop the Peddler and find the Book of the Dead. Secrets are revealed from BA’s past that complicates his mission and threatens to endanger his redemption. He must decide if he and his ally’s efforts are enough to stop the Peddler, or if he has to call on his frenemy, the Hangman, for help.