Doctor Who episode 658: The Trial of a Time Lord – Part Thirteen (29/11/1986)
‘Most of what you saw was true.’ Except all the really dramatic bits, like Peri dying. Those were all made up. I think it’s a stroke of genius to bring back the Master as the Doctor’s key witness for the defence, and Ainley doesn’t disappoint as he leers over the court room, gently flirting with the Inquisitor, mocking the Time Lords’ love of propriety, and dramatically blowing open the conspiracy to conceal the theft of Matrix secrets by devastating the Earth. This might have been enough anyway: ‘causing ripples that’ll rock the High Council to its foundations’ and ensuring no-one else has the pleasure of revenge on the Doctor is perfectly Master-ish.