The Cybermen invade the Snowcap base, killing General Cutler, but they are then defeated. Back in the TARDIS, the worn-out Doctor regenerates.
| Name | Type | Role | |
|---|---|---|---|
| Kit Pedler, Gerry Davis | Writer | ||
| Robert Beatty | Guest Star | ||
| David Dodimead | Guest Star | ||
| Dudley Jones | Guest Star | ||
| Christopher Dunham | Guest Star | ||
| Harry Brooks | Guest Star | ||
| Christopher Matthews | Guest Star | ||
| Gregg Palmer | Guest Star | ||
| Steve Plytas | Guest Star | ||
| Callen Angelo | Guest Star | ||
| Derek Martinus | Director |