Mark Cobden is sent to prison and has to learn quickly how to survive. When an inmate identifies prison officer Eric McNally's weakness, he faces an impossible choice.

Mark is being bullied by fellow inmate Johnno. Does he tell the prison officers and be labelled a grass or risk the attacks becoming more and more violent? Meanwhile, Eric's son is attacked.

Mark suffers a tragic personal loss and is given the chance to leave prison for a day. Eric is forced to take greater risks to protect his family. But where will he draw the line?

Three women are pulled into each other's orbit when they arrive at Carlingford prison.

After six months on the outside, Orla finds herself back in Carlingford. Desperate to maintain contact with her kids, she’s willing to risk extreme action. Meanwhile, Abi contemplates revenge, close to breaking point, whilst Marie-Louise encourages her to open up about her past. Reluctant to trust the other inmates, Abi steps up to help when crisis strikes. And Kelsey sets her sights on transferring to the mother and baby unit, making plans for her future in the face of uncertainty, as her due date draws closer.