An Edwardian yacht in deep space races around the planets. There is a double agent in the TARDIS crew. The White Guardian warns the Fifth Doctor of great danger. Turlough must finally choose sides and at the end of the race lies the prize of Enlightenment.

Genres

Cast

Peter Davison

The Doctor

Janet Fielding

Tegan Jovanka

Mark Strickson

Vislor Turlough

Cyril Luckham

The White Guardian

Valentine Dyall

The Black Guardian

Keith Barron

Striker

Lynda Baron

Wrack

Leee John

Mansell

Tony Caunter

Jackson

Clive Kneller

Collier