Beech and Glaze are sent to Shadwell Prison to investigate allegations that three prison officers are responsible for the assaults of two prisoners. With the prison on lockdown, they try to get through to the angry victims, but they soon face outrage from the prison officers when one of the suspended officers is burgled and another is assaulted. Glaze tries to talk to a lifer but ends up being held hostage, however he provides info after the incident about a death in custody five years earlier. One of the victims is identified as a family member of the prisoner who died five years ago, and his brother is suspected to be the man behind the burglary and assault, but they are forced to turn to one of the accused for evidence. Will he turn on his colleagues to help them solve the case?