Jamie and Ben are set to work in the mines but are determined to escape. The Doctor discovers that Zaroff's mad plans will cause the destruction of the Earth.
| Name | Type | Role | |
|---|---|---|---|
| Geoffrey Orme | Writer | ||
| Graham Ashley | Guest Star | ||
| Tony Handy | Guest Star | ||
| P.G. Stephens | Guest Star | ||
| Catherine Howe | Guest Star | ||
| Tom Watson | Guest Star | ||
| Joseph Fürst | Guest Star | ||
| Paul Anil | Guest Star | ||
| Julia Smith | Director |