DC Isobel de Pauli is transferred to the vice squad at Bridewell, Liverpool 1. Her new partner, DC Mark Callaghan, is in court for the trial of drug dealer Mikey Sullivan. De Pauli and Callaghan follow up an incident where a man was thrown from a balcony, but the victim refuses to cooperate. The squad is called to a disturbance at a club owned by a major drug supplier.

DC Callaghan and de Pauli try to trace a young girl with a conviction for prostitution who has gone missing. Both officers are interrogated about the abortive arrest of Mikey Sullivan.

DC Callaghan and de Pauli interview a convicted paedophile in connection with the disappearance of a young boy. Callaghan is appalled to learn that local drugs baron Sullivan has put money into his brother's new bar.

The vice squad investigates the murder of a prostitute. DCs Callaghan and de Pauli find their private lives dragged into the station.

DC de Pauli investigates a case of petty violence and is drawn into John Sullivan's gangland past.

A surveillance operation is threatened, and DC de Pauli is forced to choose between the job and her fiancé.