From a distance, they seem to be sleeping. Three bodies, sitting propped up against the ancient stones of Hadrian's Wall. A closer look reveals the horror of their too-white faces, and the ring of vivid red bruises around each neck. The victims were found by schoolgirl Isla Bell, out on an early morning run along the historic site. That day changed the small, close-knit community of Briganton forever, and it also shaped the course of Isla's life. Twenty years later, she's a professor of criminal psychology at the University of Northumberland. She specializes in studying the brain function of psychopaths and serial killers, wrestling with the question that still haunts her: why? Why did Heath McGowan kill those people-and two more besides-before he was finally caught by Isla's police detective father? At last, Isla has a chance to get answers. Heath, previously unforthcoming about the murders, agrees to take part in her research. Isla's husband, Ramsay-the only one of Heath's victims to survive-cautions her against the meeting. But no matter how ready Isla feels to peer within a killer's mind, there is no way to prepare for the fresh horror about to engulf Briganton. Another body is found, displayed just as before ... and then another. Is this a copycat, or could the truth be darker still?