Before leaving his post, John Stafford must complete an investigation into corruption in the Met. ACC Anne Stewart, keen for promotion to Stafford's old position, finds herself torn when a gunman unleashes terror in Burthorpe; she deals with the danger as a priority, and is late for the all-important interview. Meanwhile, Stafford meets prime contender Alan Cade.

Stafford finds an unpected ally in Cade, who assists in the corruption investigation and also impresses Rosalind Maxwell, Chair of the Police Authroity. Maxwell is charmed by the debonair officer, while fellow contender Anne has consistently failed to make a good impression; her prospects for promotion look bleak.

A dcotor is caught running a private scam, and presents more trouble by making claims about corruption involving a prominent local councillor. Cade is forced to justify his expenditure at the same time as organising a massive security operation for a royal visit, and the doctor makes matters worse by using the visit as a platform to make his allegations public.

Cade adopts a highly risky strategy in an attempt to take down local drug barons.

Following the death of an informant, criticism over the handling of the rig hijack and the acquisition of a new police command vehicle amid budget cuts, Cade is under mounting pressure. Determined not to give up, he looks to Anne Stewart for assistance.