A motorway service station on the M1: dimly lit, run down, poorly supervised, flickering lights, dark corners; a favourite stopover for long-distance lorry drivers on their way up north from London. Behind it, a body is found in a ditch, that of a girl barely out of her teens. She appears to have no family, no friends, no connections anywhere. Other girls have gone missing in the vicinity & no one has stepped forward to claim them. Anna Travis is assigned to the case. Her blood runs cold when she receives a letter from a lifer -- someone she was responsible for arresting in the past -- who writes to her from prison, asking her to visit him urgently. For he claims he knows who the killer is..