To the public, he's a hero: a brutal killer who targets sex offenders. To most of London's police force, he's the suspect in a gruesome, time-consuming case to be avoided. But to Detective Constable Maeve Kerrigan, he's a murderer--no matter the sins of his victims--and catching him is her job. Assigned to the case with the division's unreadable new DI, Josh Derwent, young and inexperienced Maeve is determined to prove she has what it takes to make it as a female in the tough world of the London police.

But for a killer who strikes with such spectacle, this one is proving remarkably elusive. And when Maeve learns his motive might be about exacting revenge, his acts of incredible violence move from abstract justice to the intensely personal, and become all the more terrifying. Unsure whom she can trust even within her own department and knowing her life is at stake, Maeve will have to decide how far she's willing to go to ensure justice is served.

Jane Casey's taut, brilliantly executed thriller will have readers on the edge of their seats from the opening chapter to the stunning conclusion.