Frost's Christmas is overshadowed by a local power station worker falling to his death in a mysterious accident, shortly after he was burgled. Then a young police detective, Tim Fox, is murdered, and Frost wonders if it really is related to the large investigation he was working on to uncover a car theft gang.

Frost continues to try to identify the detective's killer. The task is complicated by a bizarre series of pet shootings, about which he is reluctantly forced to seek help from a computer system run by a seconded new junior WPC. His pursuit leads to a confrontation high above a power station.