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 unhappy? 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?