It features university clinical psychologist, Dr Anthony "Tony" Valentine Hill (played by Robson Green), who taps into his own dark side to get inside the heads of serial killers.

Working with Carol Jordan and other detectives, Hill takes on tough and seemingly impenetrable cases in an attempt to track down the killers before they strike again.

It follows the Major Incident Team (MIT) of Bradfield Metropolitan Police's CID, and the assistance provided to the detectives by clinical psychologist and serial offender profiler Dr. Tony Hill.

A constant theme is Jordan's, and later Fielding's, struggle with their senior officers, who are often less trusting of Hill's eccentric methods and far-fetched theories than are the two detectives.

(Actor Robson Green conducted his own research for the series, during which he spent time with criminal psychologist Julian Boon.

Green described Boon in part as an "extraordinary, intelligent, nice guy who carried his life in a blue bag and traveled on a double-decker bus.

(Speaking of Norris's portrayal of Carol Jordan, Val McDermid said that she "brings real intelligence and insight to her role, demonstrating that there's a lot more to her skills than we got to see in Cold Feet.

These include Bollyhope Quarry (Durham), Chopwell Woods (Gateshead), and Eshott Hall (Northumberland), which was used for the Vance residence.