With a serial killer on the loose, DI Carol Jordan calls in clinical psychologist Dr. Tony Hill for help with the investigation, despite objections from her superiors. When a cop becomes the next victim, the case turns personal.

When two teenagers' bodies are pulled from a Northumberland tarn, Dr. Tony Hill immediately suspects a multiple killer. DI Carol Jordan is called to the home of popular chat show hosts Jack and Amanda Vance.

The murder of a young woman brings back memories of the murder of Trudy Hibbert. Known paedophile Paul Gregory was acquitted but police and locals fear he is killing again.

Tony's patient, the child killer Maggie, is on the verge of revealing where she buried her victims, but Tony and the police are distracted by a serial murder case involving the roommate of one of his students.

Tony and Carol investigate when a 500-year-old skeleton is unearthed while excavating for a hotel extension. Underneath the body, they find two more modern corpses.

Tony and Carol think they've scored early when two murders lead to one man. The trouble is that the man is in prison; could he really be controlling it all from the inside?