Fifteen years ago when Jack Delaney was a beat cop not long out of Hendon, two children went missing from Carlton Row, a small residential street in Harrow. They were never seen alive again.

Two years later Delaney rescued a young girl from the boot of an abandoned car, leading to the capture of Peter Garnier, one of the most horrific child rapists and murderers in recent history. Although the bodies were never found, Garnier admitted to murdering the two children and many, many more. He was sent to prison for the rest of his natural life.

Jack had thought the case was closed. But he couldn't have been more wrong.

This morning ... another young boy disappears from Carlton Row. Peter Garnier sends Jack the chilling message that they are both at the heart of the mystery, and Delaney has no time to figure out why, or how. Because tonight, the killings begin again ...