In December 2016, HMP Birmingham became the scene of Britain’s worst prison riot for 25 years as staff lost control of four wings and up to 600 prisoners were let out of their cells. Featuring new interviews with senior figures in the justice system interwoven with footage taken by prisoners on illegal mobile phones, this programme investigates the state of our prisons and ask why the Birmingham riot happened. It shows how the riot unfolded using never previously broadcast recordings of radio messages made by staff during the disorder. Exposure has also obtained a copy of the official report into the Birmingham riot that the Government refuses to publish. With violence in prisons at record levels, this film contains an interview with and dramatic CCTV footage of a prison officer who was attacked in jail and thrown down stairs, ending his career.