Part social drama, part knockabout comedy, this is an odd but entertaining account of British prison life in the 1950s. It's based on a 1960 TV play by Mike Watts, who used real-life experience for his story of an old lag (Ronald Fraser, the only member of the TV cast to reprise his role) who befriends new inmate Paul Massie and shows him the ropes. Their relationship appears to foreshadow the bond between Fletcher and Godber in TV's Porridge, but this hasn't dated nearly so well. However, the depiction of repetitive prison routine (the title refers to the detested practice of "slopping out") still has an impact.