As they are trying to escape from E-Space and return to normal space. The Doctor, Romana, Adric and K-9 finds themselves in a white void, where they find a ship commanded by the evil Rorvil is trapped in the void. Only to witness the fall of the Tharil Empire, where the Doctor bids to free the time sensitive Tharils who are Rorvil's slaves before Rorvik's vengeful acts brings about their annihilation.