Just as DCI Banham and DI Alison Grainger are about to get married, the previous night of street rioting culminates in a policeman being shot and all available officers are urgently called to the scene.
Banham, a trained hostage negotiator, rushes to the street when he hears his friend, PC Martin Neville, has been shot, dragged into a local warehouse and taken hostage, along with WPC Hannah Kemp and three civilians.
As Banham tries to negotiate, things go from dangerous to critical. PC Neville is in a life-threatening condition, and the clock is ticking to get him to hospital.
Meanwhile Grainger, having been left at the alter and told not to join the siege, defies orders and is at the station working on the case from the CCTV room. When the pieces begin to fall together, she goes off on her own, only to find herself, too, in a life-threatening situation.
Time is nearly up, and the demands of the hostage-takers are yet to be met. Banham is losing his mind with worry. He has six lives at risk. And, by a very unexpected turn in circumstance, their fate is now in someone else's hands.