When Steve Arnott is transferred to a police anti-corruption unit, he finds his target is the city's top detective, Tony Gates. Can Gates really be as good as he appears? Arnott must engage in a cat-and-mouse struggle to uncover Gates' secret.

Having been duped into covering up Jackie's crime, Gates is desperate to sever ties with her. But, as Arnott and Fleming close in on his secret, Gates is plunged into an even more dangerous situation than he first thought.

Arnott is convinced Gates played a part in Jackie's disappearance. With Fleming's help, the anti-corruption team tries to trap Gates into revealing his involvement in covering up Jackie's crimes.

Desperate for proof of Gates's corruption, Fleming pushes her relationship with him to the limit. But her behaviour causes Morton to question if she might not be such a loyal colleague after all.

With Gates on the run, the anti-corruption team come under pressure to close the case once and for all. Arnott is forced to make some tough decisions about where his loyalties lie. Fleming and Hastings go all out to catch Gates, leading to a shattering conclusion.