The moonbase is cut off from Earth and under siege. The Cybermen launch an all-out attack and the Doctor formulates a dangerous plan to repel the invaders.
| Name | Type | Role | |
|---|---|---|---|
| Gerry Davis, Kit Pedler | Writer | ||
| Michael Wolf | Guest Star | ||
| Derek Calder | Guest Star | ||
| Keith Goodman | Guest Star | ||
| Robin Scott | Guest Star | ||
| Sonnie Willis | Guest Star | ||
| Alan Wells | Guest Star | ||
| John Wills | Guest Star | ||
| Peter Greene | Guest Star | ||
| Patrick Barr | Guest Star | ||
| André Maranne | Guest Star | ||
| Victor Pemberton | Guest Star | ||
| Morris Barry | Director |