A murder inquiry is close to the hearts of the officers at Brazen Gate CID; tempers become frayed as they search for their colleague's killer. The discovery of an old tape of a suspect being interviewed provides a way for the department to come to terms with their loss.

A terminally ill cancer patient is found murdered in his hospital bed. Becky and Warren are sent to investigate a violent rape case, but the victim knows more than she is prepared to admit.

Bruce raises concerns about Frankie's health. Warren & Becky are puzzled as to why someone should be collecting the mail and bringing fresh flowers to a man who's been dead for 2 months. Frankie follows up a tip-off about a planned robbery on a pub. Marty takes matters into his own hands after a suspect gives him the run-around, but gets more than he expects in return.

An investigation into the origin of pornographic images found on Ron's daughter's computer leads the team to a murder scene. Bruce starts to feel the pressure and Frankie refuses to take a back seat, despite having been suspended from duty.

Relations are strained between Ron and Marty after Ron discovers who spilled the beans on his affair. They find themselves in further trouble when the suspect they've just arrested collapses of a heart attack. Members of a hostile and divided community seem intent on blaming each other when a prominent human rights lawyer is shot and her body moved from the scene of the crime. Frankie tries to strike a deal with his informant in order to find out who supplied the gun. Not satisfied with the results, he goes it alone and goes undercover on his own private mission – with devastating results.

A woman is found dead in a bus shelter outside her own home, but the neighbours are reluctant to get involved. Frankie's disappearance leads his colleagues to reopen an old case, after it becomes apparent that Frankie has been running his own inquiry. A shop-keeper at the end of his tether resorts to drastic action in order to be taken seriously. Ron's personal life becomes the talk of the department after Marty reveals Ron's secret.