Hancock's Half Hour is a BBC radio comedy, and later television comedy, series of the 1950s and 60s written by Ray Galton and Alan Simpson. The series starred Tony Hancock, with Sid James; the radio version also co-starred, at various times, Moira Lister, Andrée Melly, Hattie Jacques, Bill Kerr and Kenneth Williams. The final television series, renamed simply Hancock, starred Hancock alone. Comedian Tony Hancock starred in the show, playing an exaggerated and much poorer version of his own character and lifestyle, Anthony Aloysius St John Hancock, a down-at-heel comedian living at the dilapidated 23 Railway Cuttings in East Cheam. The series was influential in the development of the situation comedy, with its move away from radio variety towards a focus on character development.

An upper-crust family dinner is interrupted by a police inspector who brings news that a girl known to everyone present has died in suspicious circumstances. It seems that any or all of them could have had a hand in her death. But who is the mysterious Inspector and what can he want of them?