Mick Revill has done time for armed robbery, but has kept his nose clean after his release from prison making money as a debt collector. But Neil Boon thinks he goes too far when performing his duties and ask the police to look into it. PC Younger has problems with his lack of authority and reluctantly accepts Revill's offer to train him as a boxer. PC Wetherby attempts to enter him in the upcoming police boxing tournament, but has his plan backfire on him. David gets invited to the centenary celebrations of his old school and Aunt Peggy is determined to make him go. But David doesn't want to especially after meeting one of his old class mates who has really made it big.