With Tegan and Richard under alien control, and the manor sealed against anyone leaving or entering, it's a question whether or not the Doctor can get to London before the Terileptils release their improved strain of black death upon the world.
| Name | Type | Role | |
|---|---|---|---|
| Eric Saward | Writer | ||
| Eric Dodson (Headman) | Guest Star | ||
| Michael Robbins (Richard Mace) | Guest Star | ||
| James Charlton (Miller) | Guest Star | ||
| Michael Melia (Terileptil) | Guest Star | ||
| John Savident | Guest Star | ||
| Valerie Fyfer (Elizabeth) | Guest Star | ||
| Peter Van Dissel | Guest Star | ||
| Neil West (Poacher) | Guest Star | ||
| Anthony Calf | Guest Star | ||
| John Baker | Guest Star | ||
| Peter Moffatt | Director |