The crew go to the planet Ultraworld, only to discover it is a mental reprocessing plant. Vila saves the crew by telling riddles to Orac.
| Name | Type | Role | |
|---|---|---|---|
| Trevor Hoyle | Writer | ||
| Ian Barritt | Guest Star | ||
| Ronald Govey | Guest Star | ||
| Peter Richards | Guest Star | ||
| Stephen Jenn | Guest Star | ||
| Vere Lorrimer | Director |