The show was a science fiction satire based on the characters of Don Quixote, with astronaut Captain Don Quick (Ian Hendry) and Sergeant Sam Czopanser (i.e. "Sancho Panza") (Ronald Lacey), members of the "Intergalactic Maintenance Squad". On each planet they visit, Quick attempts to set right imaginary wrongs, often upsetting the inhabitants of whatever society he is in. The plot bears some resemblance to the five Penton and Blake stories by John W Campbell, about two astronauts who travel the Solar System meeting strange races.