As the Silurian plague quickly spreads, the Doctor desperately searches for a cure. But the Silurians are aware of the Doctor's efforts and intend to stop him.
| Name | Type | Role | |
|---|---|---|---|
| Malcolm Hulke | Writer | ||
| Geoffrey Palmer | Guest Star | ||
| Nigel Johns | Guest Star | ||
| Brendan Barry | Guest Star | ||
| Alan Mason | Guest Star | ||
| Timothy Combe | Director |