Lord Slaadek’s plan to revive Ice Warrior civilisation reaches crisis point, while an old enemy forces the Doctor into a brutal moral test.
| Name | Type | Role | |
|---|---|---|---|
| Susan Brown | Guest Star | Margaret | |
| Tracy-Ann Oberman | Guest Star | Temperance Finch | |
| Niky Wardley | Guest Star | Tamsin Drew | |
| Nick Wilton | Guest Star | Harold | |
| David Warner | Guest Star | Professor Boston Schooner | |
| Nicholas Briggs | Guest Star | The Ice Warriors | |
| Nicky Henson | Guest Star | Gregson Grenville | |
| Jack Brown | Guest Star | Pilot |