After receiving a warning from the White Guardian, the Doctor initially believes the TARDIS has landed aboard an Edwardian clipper ship - but all is not as it seems. While the time travellers are caught up in the omnipotent Eternals' race for the ultimate prize, the Black Guardian's scheme to destroy the Doctor enters the end-game - but which side is Turlough a pawn of?
| Name | Type | Role | |
|---|---|---|---|
| Barbara Clegg | Writer | ||
| Clive Kneller | Guest Star | ||
| Christopher Brown | Guest Star | ||
| Cyril Luckham | Guest Star | ||
| Keith Barron | Guest Star | ||
| James McClure | Guest Star | ||
| Fiona Cumming | Director |