On the planet Dido, the Doctor, Ian and Barbara meet two survivors from a crashed spaceship who are terrorised by the monster Koquillion.
| Directing | Christopher Barry | Director |
| Writing | David Whitaker | Writer |
| Writing | Dennis Spooner | Script Editor |
| Production | Verity Lambert | Producer |
| Production | Mervyn Pinfield | Associate Producer |
| Sound | Tristram Cary | Music |
| Costume & Make-Up | Daphne Dare | Costume Design |
| Costume & Make-Up | Sonia Markham | Makeup Artist |
| Art | Raymond Cusick | Production Design |
