Let the marketing blurbs for The Demonologist breathlessly bait readers with the usual suspects. ("It's Rosemary's Baby meets The Da Vinci Code by way of The Exorcist and The Historian!")

Author Andrew Pyper would rather tell you what dark, forbidden deeds the book feels like. As effective sales pitches go, this would do Lucifer proud.

"It's a bit like stepping out on your partner or going to Tijuana for a weekend," he says when describing how the thriller has been embraced in Canadian literary circles. "The early sense is support, that practitioners or readers who normally don't read this sort of book ... are making it a happy exception. I'm their fun sin."