Determined to stop the Cybermen and the energy drain, General Cutler prepares to launch the deadly Z-bomb. Ben and Polly desperately try to stop the launch as the countdown begins.
| Name | Type | Role | |
|---|---|---|---|
| Kit Pedler, Gerry Davis | Writer | ||
| Christopher Dunham | Guest Star | ||
| Steve Plytas | Guest Star | ||
| David Dodimead | Guest Star | ||
| Ellen Cullen | Guest Star | ||
| Dudley Jones | Guest Star | ||
| Robert Beatty | Guest Star | ||
| Callen Angelo | Guest Star | ||
| Christopher Matthews | Guest Star | ||
| Derek Martinus | Director |