Castrovalva — Christopher H. Bidmead

Still weak and confused after his fourth regeneration, the Doctor retreats to Castrovalva to recuperate. -- But Castrovalva is not the haven of peace and tranquility the Doctor and his companions are seeking. Far from being able to rest quietly, the unsuspecting time-travellers are caught up once again in the evil machinations of the Master. -- Only an act of supreme self-sacrifice will enable them to escape the maniacal lunacy of the renegade Time Lord.