Sgt. Danny Waldron and his team of armed officers are deployed to detain Ronan Murphy, a suspect wanted in connection with a plot to commit a gangland execution. Waldron orders a 'hard stop' on the suspect's vehicle, forcing the suspect to decamp into a nearby housing estate. Waldron gives chase, but catches up with him long before his team arrive. Waldron decides to shoot the suspect in cold blood, despite him having already surrendered his gun, and fakes the scene to make it look like he opened fire before he was shot. When Waldron's team arrive, he orders them to discharge their weapons. Under interrogation from AC-12, Waldron looks to have an answer for everything, until DS Arnott's line of questioning into his private life begins to spook him. Hastings agrees to send Fleming undercover as a new member of Waldron's squad in an attempt to uncover the truth.