A massacre in the Scottish Highlands is far more than the family tragedy it first appears to be, in this riveting police procedural.

The slaughter of the Dawson family seems to be a heartbreaking case of murder-suicide—another deeply troubled man who violently snapped and killed his wife and children before ending his own life. But DI Alec McKay doesn’t think it’s as open-and-shut as it looks. Why was a BMW parked at the Dawsons’ holiday home on that last day of tourist season—and why are its owners also now dead? Why is the new senior investigating officer acting so erratically? And most chillingly of all, who is sending out packages containing toys taken from the crime scene?

Before McKay can close the case, he will have to face down a threat from the past—and a crime that could shatter his heart—in this twist-filled thriller from the acclaimed author whose previous police procedurals, written under the name Michael Walters, were praised as “pulse-pounding” (Chicago Tribune) and “compulsive reading” (The Independent).