Turlough allies with the Black Guardian

Tags: Fifth Doctor, Turlough, The Black Guardian, The Brigadier

Mawdryn Undead, episode 1
1 February 1983

Turlough: an alien political refugee hiding at an English private school. Knocked unconscious by a car accident, he's about to meet two beings from the Doctor's past - one pure chaos and destruction, the other one of the Time Lord's oldest allies.