The Doctor takes Peri to Titan 3, a desolate hunk of rock in space where he hopes to find some solitude for a while. Instead he finds the lone but unconscious survivor of a recent spaceship crash in sight of a mound-shaped complex where no formalised structure should exist.
| Name | Type | Role | |
|---|---|---|---|
| Anthony Steven | Writer | ||
| Andrew Conrad | Guest Star | ||
| Maurice Denham | Guest Star | ||
| Kevin R. McNally | Guest Star | ||
| Oliver Smith | Guest Star | ||
| Barry Stanton | Guest Star | ||
| Gavin Conrad | Guest Star | ||
| Peter Moffatt | Director |