The Master reveals to the trapped Adric that he has a further trap set for the Doctor. Tegan searches the TARDIS computer systems and finds a place named the Dwellings of Simplicity on Castrovalva which will be a suitable place for the Doctor to recover from his regeneration, but when they arrive the Doctor vanishes!
Realising the true nature of Castrovalva's reality, The Master, seeing all is lost, flees to his TARDIS. The Doctor and his companions flee from the city, but who will survive as the city collapses in on itself...
Nyssa and Tegan follow the trail of blood away from the Cabinet, trying to find the Doctor while avoiding the feathered warriors in the forest. They eventually spot the Doctor some distance away, but although they call out to him he doesn't recognize his own name. The warriors take the Doctor into Castrovalva with them, but Nyssa and Tegan arrive seconds too late.
The Doctor returns to Gallifrey, only to discover that a deadly game banned and derelict for centuries, has been reactivated. Soon he finds his other selves have also been summoned to assist him in tracing the culprit and tracking down the mysterious secret of Rassilon...
The Master and the Doctor fight for control over Kamelion's mind while Turlough and Tegan make new allies in the castle in an attempt to avoid the iron maiden.
