With the Inquisitor (Lynda Bellingham) overseeing the proceedings, it was the Valeyard (Michael Jayston) who proved the greatest threat, hiding his own sinister motives for wanting the Doctor's downfall.
Doctor Who: The Collection – Season 23 (The Trial of a Time Lord) includes the following stories from 1986:
The Mysterious Planet
Mindwarp
Terror of the Vervoids
The Ultimate Foe
Joining Baker[...]
