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.
The Doctor and a newly-regenerated Romana arrive on Skaro to find that the Daleks, locked in a war with the robotic Movellans, have returned to retrieve their buried creator Davros.