Lindsay is remanded in custody where she is victimized by both staff and prisoners. Meanwhile Steve and Kate discover the identity of the dead witness from blunt inspector Cottan. He was known as Tommy and Cottan believes that Jayne Akers, his liaison officer, was the real mole who betrayed the escort. Kate visits Lindsay, who knows about her affair with Jayne's husband whilst Cottan has similar suspicions. Lindsay's accusations also cause friction between Hastings and Steve, whilst Dryden's driving offence attracts the press so to save himself he strikes a deal naming Lindsay as the officer under investigation. Kate discovers a body, apparently that of the missing Carly, and returns to see Lindsay, who claims her ex-lover Dryden set her up. Kate makes a call which seems to support this whilst Cottan gets evidence to prove Jayne was on the take.

A new witness comes forward claiming to have crucial evidence in Gail Vella's murder. Kate is torn between her loyalty to Jo and to AC-12.

As AC-12 struggle to deal with the repercussions of tragic events, Hastings makes one final bid to uncover institutionalized corruption.

With time running out, AC-12 attempt to unmask 'H',the fourth individual commanding the network of corrupt officers.