The TARDIS arrives on the planet Terra Alpha, where the Seventh Doctor and Ace discover a society in which sadness is against the law - a law enforced zealously by the brightly uniformed Happiness Patrol. The planet is ruled by Helen A with the aid of her companion, Joseph C, and her carnivorous pet Stigorax, Fifi.

casts

Sylvester McCoy

Sophie Aldred

Sheila Hancock

Ronald Fraser

Georgina Hale