The Doctor and Vicki enlist the aid of the Chumblies to rescue Steven from the Drahvins and then find a way off the planet before its destruction.
| Name | Type | Role | |
|---|---|---|---|
| William Emms | Writer | ||
| Pepi Poupée | Guest Star | ||
| Lyn Ashley | Guest Star | ||
| Tommy Reynolds | Guest Star | ||
| Brian Madge | Guest Star | ||
| Angelo Muscat | Guest Star | ||
| Robert Cartland | Guest Star | ||
| Peter Holmes | Guest Star | ||
| Bill McAllister | Guest Star | ||
| Bill Lodge | Guest Star | ||
| Marina Martin | Guest Star | ||
| William Shearer | Guest Star | ||
| Susanna Carroll | Guest Star | ||
| Stephanie Bidmead | Guest Star | ||
| Derek Martinus | Director |