In this first episode, shop workers are left terrified when two men, one armed with a meat cleaver, the other with a kitchen knife, launch separate violent crime sprees robbing store tills for quick wads of cash. Humberside Police must now find both perpetrators before they strike again.

In Grimsby, CCTV shows a man bursting into a busy shop armed with a meat cleaver. But with his hood pulled down over his face detectives must now uncover his identify. DC Andy Taylor and DS Ryan Johnson investigate a theory that the suspect could live nearby. It's vital they find the clothing worn in the robbery and then link it to their emerging number one suspect.

In Hull, another man, making no attempt to hide his identity, robs a Post Office armed with a large kitchen knife - and prepared to use it. Police quickly link him to other recent violent robberies. But with no fixed address, how do they trace him? When news of a possible sighting comes in PC Hannah Saleh acts fast.

Detectives finally sit eye to eye with each suspect in separate interview rooms. Have the police found enough evidence? Will the cases stand up? Will the suspects walk, or face the full force of the law? It's down to tough questioning and nerves of steel.