databank
900 year diary
castrovalva
A beautiful and peaceful green planet in Andromeda, on which the Master created a trap for the Doctor. This took the form of a city, also called Castrovalva, created from Block Transfer Computations with built-in recursive occlusion to confuse the Doctor after his regeneration. The Doctor exposed the Master's plan and freed the trapped Adric, whose mathematical excellence the Master was exploiting to keep the city in existence. With Adric freed, the people and city began to dissolve, apparently trapping the Master within itself.