Nursing his terminally-ill wife, Det Insp ""Jack"" Frost's life becomes more stressed when, during a missing-child investigation, he unearths evidence on a 30-year-old case involving a skeleton chained to a locked strongbox that turns out to be empty.

Frost investigates the murder of a teenage girl, and the case of a woman who has been receiving threatening phone calls. Meanwhile, at the Denton police station, there are threats, deaths, arson and a staff shortage.

Frost investigates an MP's son who is involved in a hit-and-run accident, and a robbery at a private casino, which occur on the same night. He gets a humorless new partner to assist him.

Frost is assigned a new, West Indian detective constable, Clive Tanner; transferred in to help him investigate a string of commercial burglaries, which leads him to a black family on the local Eastdean estate, that he calls ""the crime academy"", while feeling guilt over the death of one of his informants. Will the arrest of the apparent culprit lead to accusations of police racism?

Frost investigates a series of break-ins and brutal attacks at the homes of elderly people. He is helped by a female detective, DS Lawson, who also offers him advice on his personal life.

Upon investigation, Frost discovers that the apparently accidental death of a drug addict was actually murder. He also decides to confront an aspect of his own past.

Frost is invited to join fellow George Cross recipients in London. He is instructed to enlist the aid of WPC Hazel Wallace as a decoy to catch a serial rapist, but it exposes her to serious danger.