A 19-year-old youth, JR (Brenton Thwaites) is sent to an Australian correctional facility for six months as punishment for a minor crime. He finds his cellmate is being sexually abused by another group of prisoners led by a man named Dave. JR also meets the charismatic Brendan Lynch (Ewan McGregor), a notorious Scottish armed robber. Lynch is playing a game of correspondence chess when a passing JR points out an unseen checkmate against Lynch. Later, JR finds his cellmate sharpening a shiv with the intention of defending himself against Dave. When Dave and his gang move to attack the cellmate, JR prevents the attack by initiating a fight. Lynch scolds JR for meddling, and soon after, JR's cellmate is once again sexually assaulted. His cellmate attempts to commit suicide and he is hospitalized, causing Dave to focus his sexual attacks on JR. When Dave and his gang try to rape JR, Lynch and his men, Sterlo (Matt Nable) and Merv (Eddie Baroo), rescue JR and kill Dave. In exchange for Lynch's protection during JR's sentence, JR agrees to perform tasks for Lynch once he gets out of prison.