The Doctor and his companions are on board an Earth ship trapped in orbit around the Sense-Sphere when it is boarded by the Sensorites, who steal the lock mechanism from the TARDIS.
| Name | Type | Role | |
|---|---|---|---|
| Peter R. Newman | Writer | ||
| Ilona Rodgers | Guest Star | ||
| Lorne Cossette | Guest Star | ||
| Joe Greig | Guest Star | ||
| Ken Tyllsen | Guest Star | ||
| Stephen Dartnell | Guest Star | ||
| Mervyn Pinfield | Director |