The Doctor, Romana, Adric and K9 encounter the enslaved time-sensitive Tharils, who lead them to a white void occupied only by the ruins of an old building and a spaceship - a dimension that might be the key to escaping E-Space.
Tom Baker , Lalla Ward , Matthew Waterhouse , John Leeson , Clifford Rose , Kenneth Cope , David Weston , Jeremy Gittins
BBC