When the Second Doctor, Polly, Ben and Jamie visit a human colony that appears to be one big holiday camp, they think they have come across a truly happy place. Yet a shadowy presence soon makes them realise that the surface contentment is carefully controlled.

• BBC
• Patrick Troughton
• Anneke Wills
• Michael Craze
• Frazer Hines
• Peter Jeffrey
• Graham Armitage
• Ian Fairbairn
• Jane Enshawe