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.
Romana fancies a proper holiday and convinces the Doctor to visit the leisure planet Argolis, where a takeover by the Argolins' historic enemy is underway.
