The story takes place in a Welsh holiday camp in 1959. Delta, the last of the Chimeron race, is being pursued by Gavrok and the Bannermen, who intend to kill her.
The story was written by Malcolm Kohll and directed by Chris Clough. The cast also includes Belinda Mayne (Delta), Don Henderson (Gavrok), Brian Hibbard (Keillor), David Kinder (Billy) and Ken Dodd (Tollmaster).
See also List of Doctor Who serials