Natalie Vine, one of Britain's top forensic psychiatrists, spends every day trying to get inside the heads of some of the most violent criminals imaginable. It's lonely, harrowing work, but perhaps it helps her deal with the demons of her past.

Locked in the mind of Thomas Meredith are terrible visions of how a serial killer tortured and murdered his girlfriend, in front of his very eyes, a year earlier. Once a doctor, Meredith has become a recluse who only emerges from his isolated home to work the graveyard shift in a local motorway cafe. Natalie Vine is the one person with the ability and empathy to make Meredith open up, to bring to the surface the horror that he has buried so deeply. And she must succeed, no matter how much pain it causes.

For Meredith is the only living witness to this murderer's actions, and he has started killing again...