The Doctor, Vicki and Steven arrive on an arid planet where they meet the beautiful Drahvins and the hideous Rills. Each has crash-landed after a confrontation in space. The Rills are friendly, compassionate explorers. The Drahvins are dull-witted, cloned soldiers, terrorised by the intelligent, warlike matriarch Maaga.
| Writing | William Emms | Writer |
| Directing | Derek Martinus | Director |
| Directing | Mervyn Pinfield | Director |
| Writing | Donald Tosh | Script Editor |
| Production | Verity Lambert | Producer |
| Sound | Les Structures Sonores | Music |
