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.

Tony and Carol reunite when the years-old corpse of a teenage girl is found. Carol is also pulled into investigating hate mail sent to a popular TV personality couple, Jack and Amanda Vance. After a murder at the Vances' house, Tony becomes convinced that the two cases are connected.

The 500-year-old skeleton of a girl is discovered at a new hotel site, but forensics show that the corpse was recently moved. The case becomes even more perplexing when the bodies of a young couple are found buried underneath it.

While Tony and Carol search for the killer of a young Dutch nurse, the best friend of one of Tony's students goes missing. Meanwhile, Tony gets closer to discovering where his child-killer patient, Maggie, buried her victims.

Tony returns home from a disappointing book tour to assist Carol in her investigation of a divorced woman's violent death. When another victim turns up-this time an elderly man-Tony struggles to find a connection.

After being hit on the head by a suspect, Tony undergoes a neurological exam and receives a surprising result. Carol tracks a serial killer who shoots his victims from afar and leaves a playing card at the scene.

When Tony responds to a violent incident at a mental hospital, he believes the inmate was triggered by news of a prostitute's brutal murder. With more victims and no leads, DC Paula McIntyre volunteers to go undercover in a sting operation.

When lawyers drag up an old case, Tony contacts Carol only to learn that she's moved out of the country. Carol's replacement, DI Alex Fielding, is investigating the death of a woman stuffed into a barrel but is reluctant to accept Tony's input.

Follows a single sprawling drug investigation in Baltimore, against the backdrop of the mayor's reelection campaign. Told from the point of view of both the police and their targets, where easy distinctions between good and evil are challenged at every turn.

An elderly woman is murdered in her home with no obvious motive. Although Alex and Tony quickly identify a suspect, his domineering mother impedes their investigation. Meanwhile, Tony's friend and fellow psychologist visits from America.