February, 1918. In the small hours of a cold morning, a burglary in Limehouse has escalated into a sinister siege between a band of thieves and the authorities, and a police constable lies dead. Detective Inspector Harvey Marmion and Detective Sergeant Joe Keedy hasten to the scene where attempts at talking the men into surrendering have been met with stony silence. When the door is eventually battered down, Keedy bravely leads the way in. Then a gunshot is heard: Keedy has been hit.

While his partner is rushed to hospital, Marmion is on the trail of the burglars, following leads as to their previous targets and overall goals. As defenceless Keedy remains in the sights of the murderous thieves, Marmion delves into the secrets that lie behind this fatal incident...