On the Moon, the Doctor is captured by the Ice Warriors as he spacewalks to the T-Mat relay station. He learns that they intend to use T-Mat to spread a deadly fungus across the world.
| Name | Type | Role | |
|---|---|---|---|
| Brian Hayles | Writer | ||
| Steve Peters | Guest Star | ||
| Christopher Coll | Guest Star | ||
| Tony Harwood | Guest Star | ||
| Alan Bennion | Guest Star | ||
| Ronald Leigh-Hunt | Guest Star | ||
| Louise Pajo | Guest Star | ||
| Ric Felgate | Guest Star | ||
| Terry Scully | Guest Star | ||
| John Witty | Guest Star | ||
| Philip Ray | Guest Star | ||
| Sonny Caldinez | Guest Star | ||
| Michael Ferguson | Director |