The death of Peri

Tags: Sixth Doctor, Peri Brown, The Valeyard, Sil

The Trial of a Time Lord: Mindwarp, episode 8
25 October 1986

Crozier has been tasked with copying the brain of the dying Lord Kiv into a new host body. With Kiv’s condition worsening, he has succeeded in a direct transfer into Peri - overwriting her brain with that of the alien - killing her. As the Doctor watches on helpless, events escalate out of control. With the future of all life in the universe in the balance, the Time Lords have only one option left...