Deep space, the distant future: following Earth's devastation by solar flares, the survivors of mankind are in cryogenic suspension aboard the Nerva Beacon space station. The Doctor, Sarah and Harry arrive on board and are greeted with suspicion by the awakening survivors… just as the menace of the insectoid Wirrn becomes apparent.
| Name | Type | Role | |
|---|---|---|---|
| Robert Holmes | Writer | ||
| Wendy Williams | Guest Star | ||
| Kenton Moore | Guest Star | ||
| Christopher Master | Guest Star | ||
| Rodney Bennett | Director |