The Trial of a Time Lord: Part 12

The Trial of a Time Lord: Part 12

Available on BritBox, Prime Video, Tubi TV
S23 E12: The Doctor realises that if he can speed up the Vervoids life span with light, they will decay. Using vionesium, he does so, unwittingly causing genocide in the process...
Starring Michael Jayston, Honor Blackman, Michael Craig