The film is a semi-autobiographical narrative inspired by the real-life experiences of Ronnie Thompson, a former prison officer who spent seven years working in some of the UK’s most perilous prisons. Adapted from Thompson’s book with the same title, the film features performances by James D’Arcy (known for Master & Commander), Noel Clarke (from Kidulthood), Frank Harper (The Football Factory), Jamie Foreman (Layer Cake), Andrew Shim (This Is England), and Kate Magowan (Stardust). The plot follows ex-soldier Sam Norwood, who, after returning from Iraq, takes up a position as a prison guard and finds himself immersed in the dark world of prison life, encountering corrupt officers and drug smuggling.