The Doctor, Steven and Dodo have travelled 700 years into the future and find that the Ark is now under the control of the Monoids as it approaches Refusis.
| Name | Type | Role | |
|---|---|---|---|
| Paul Erickson | Writer | ||
| Edmund Coulter | Guest Star | ||
| Terence Bayler | Guest Star | ||
| Frank George | Guest Star | ||
| Brian Wright | Guest Star | ||
| Eileen Helsby | Guest Star | ||
| John Halstead | Guest Star | ||
| Terence Woodfield | Guest Star | ||
| Michael Imison | Director |