Ronald and Reginald Kray were the foremost perpetrators of organized crime in the UK from the 1950s until their incarceration in 1969. Featuring personal correspondence and recorded phone calls, collected over a decade, alongside new and exclusive interviews with those closest to Ron and Reg, including Charles Bronson, Maureen Flannagan, and Dave Courtney, this film provides an intricate, personal and horrifying portrait of the Krays behind bars.