A death row inmate, Reggie Tifford, requests to speak with Hawkes on the night of his execution in order to confess that he murdered Hawkes' sister. During the execution, a guard begins to convulse and dies which delays the execution process, buying Reggie extra time which makes Hawkes believe he had something to do with the guard's death. After the failed execution, a rogue State Trooper releases all the inmates from their cells, which causes a riot and locks down the prison with Hawkes inside. The only man that can help Hawkes get through this riot alive is the man who killed his sister. Mac and the team work to figure out a way to break Hawkes out of the prison while Hawkes struggles with trusting his sister's killer. In the chaos of the riot, Hawkes sees a familiar face, Shane Casey (played by Edward Furlong), the imfamous serial killer. Hawkes searches Casey's cell and discovers that Casey was the one that poisoned the guard in order to create a diversion so that the State Trooper, an unwilling participant whose family Casey's accomplice was holding hostage, could start the riot and help Casey escape. Hawkes and Reggie race to stop Casey from escaping while trying to stay alive buring all the mayhem. Reggie physically tries to takedown Casey but Casey, wearing an NYPD uniform the Trooper gave him and Danny's badge (stolen in episode #612) manages to convince the tactical team outside the prison that he is a fellow officer being attacked by a prisoner. The tactical team shoots and kills Reggie, and Hawkes tries to stop Casey, but since Hawkes is dressed as a prisoner the officers ignore his warnings; allowing Casey to disappear into the crowd of officers. Mac and the team begin a manhunt to find Casey and put him back in prison before he kills again.