The Doctor hatches a dangerous plan to kidnap Professor Zaroff and encourages the Fish People to revolt against their masters and put a stop to the production of food.
| Name | Type | Role | |
|---|---|---|---|
| Geoffrey Orme | Writer | ||
| Roma Woodnutt | Guest Star | ||
| Paul Anil | Guest Star | ||
| Catherine Howe | Guest Star | ||
| Tony Handy | Guest Star | ||
| Joseph Fürst | Guest Star | ||
| Tom Watson | Guest Star | ||
| P.G. Stephens | Guest Star | ||
| Julia Smith | Director |