Harper Curtis is a drifter in Depression-era Chicago who finds a key to a house that opens onto other decades. Inside is a room cluttered with keepsakes, each tied to a woman he is meant to murder. He visits each girl as a child and leaves her a small token. Years or decades later he returns to kill her, planting a memento taken from another victim at the scene.
In 1989 he stabs Kirby Mazrachi and leaves her for dead, but she survives. Four years on, with the case unsolved and her attacker still a stranger to her, Kirby talks her way into an internship at the Chicago Sun-Times under reporter Dan Velazquez. She starts tracing the killings herself, matching decades of unrelated murders to a single pattern nobody else has noticed.
The novel alternates between Harper's kills and Kirby's investigation, cutting between the 1930s and the early 1990s as the gap between them closes. It plays its time travel as plain fact rather than a puzzle to unpack. The story stays close to the violence rather than looking away from it: this is a hard, propulsive thriller, not a gentle one.
It won the British Fantasy Award for Best Horror Novel in 2014.