Immortal sidhe Tuulois MacColewyn is living rough. After nearly two centuries of life as one of Faerie Queen Titania's prized wolves and a handful of years as a Roaring Twenties mob boss's favorite enforcer, he's now exiled to New York, making rent doing dirty jobs for other fey outcasts. He used to consult on the occult for Detective James Corhagen at the NYPD, but since their highly combustible friendship burned itself out a year ago, Cole hasn't heard from him.
All that changes when Corhagen summons Cole right out of his shower and into the middle of a crime scene. The NYPD is facing a rash of messy black-magic murders, complete with exploding hearts and very little forensic evidence, not to mention the sinister disappearance of several half-fey children. However hard he tries to deny it—and his inconvenient attraction to the sidhe—Corhagen needs Cole's help. A persistent police inspector rounds out the team, but when their investigation comes too close to the truth, suddenly it's their lives on the line. With a powerful killer on the loose, Cole, James, and Inspector Vallimun must race against time to stop the monster out to claim the thirteenth child.