The Making of The Trial of a Time Lord: Part Four - The Ultimate Foe

 was the fourth and final documentary in the Making of The Trial of a Time Lord series. As the name suggested, it concerned itself with the making of The Ultimate Foe.

Topics discussed
The documentary opened with Colin Baker enthusing about the idea of The Ultimate Foe as "precisely the sort of Doctor Who [he'd] always wanted to do" because of its surreal and paradoxical content.

There then ensued a discussion of the writing problems that plagued the story, given that Robert Holmes had died having only completed episode 13, and Eric Saward was fighting with John Nathan-Turner to protect Holmes' original ending. Pip and Jane Baker then offered their recollections surrounding how they came to write episode 14.

Director Chris Clough talked about the technicalities of filming the beach scenes with Colin Baker and Michael Jayston. Clough then went on to talk about why certain buildings had been chosen for location filming, and why the main "Fantasy Factory" location was actually more relevant to the original episode 14 script by Saward and Holmes.

Clough, Jayston, Baker and Tony Selby then went on to tell a few stories about actor Geoffrey Hughes.

Hickman and Sangster then talked about how the Matrix, the Valeyard and the Master were used in the story, and Colin Baker wrapped up proceedings by musing over the appropriateness of "carrot juice" as a Doctor's final words.