EPISODE: The Mind of Evil: Episode Three
OVERALL EPISODE NUMBER: 285
STORY NUMBER: 056
TRANSMITTED: 13 February 1971
WRITER: Don Houghton
DIRECTOR: Timothy Combe
SCRIPT EDITOR: Terrance Dicks
PRODUCER: Barry Letts
FORMAT: VHS: Doctor Who - The Mind of Evil [VHS] 
Episode Format: 16mm b&w film recording
The Doctor overpowers Chin-Lee removing the device that links her to the Keller machine and severing the Master's control over her, saving the life of the American delegate. Prison officers, with a little help from Jo Grant, regain control of the prison wing but when the Master, in the guise of Emil Keller, arrive he helps Mailer seize the entire prison. The Doctor is captured when he arrives to collect Jo and is chained to the Keller machine which subjects him to images of many of his foes.
And with one bound the peace conference is gone from the story, which effectively exposes it as some padding to stretch the rest of the story out to 6 episodes. As it is, it's being here is quite useful as it helps set the international tone for the third Doctor's stay on Earth a theme we'll return to in the Day of the Daleks as Unit acts as security for another peace conference. While we're on the subject of padding: why else do the guards regain control of the prison wing only to loose it again mere minutes later? Yes it gets the Master in to fix the Keller Machine but why not have him there from before the prison is initially seized. Odd. Liz remarked that Pertwee's performance at the end of the episode doesn't look like the Keller machine is subjecting him to his worst nightmares. Quite the contrary in fact by the way he's wrything around!
Since this episode has most of the story's cast in it's the best place to look at the actors involved. Hayden Jones, mailer's henchman Vosper had voiced the Autons in Terror of the Autons and would have played the phone engineer there too if this better role hadn't been offered him. Michael Sheard is Dr. Summers, his second Doctor Who role after Rhos in the Ark. He look rather different without his moustache, I think this is the only time I've ever seen him clean shaven! Our old friend Dave Carter is one of the Prison Officers while one of the others, Bill Matthews was Davis the Silurians. This is the only Doctor Who appearance for Pik Sen Lim, Captain Chin Lee. She's the wife of Don Houghton and helped Jon Pertwee with his Hokkian Chinese dialogue in the scenes in episodes 2 & 3. Simon Lack, who was Professor Kettering in episode 1, later returns as Zadek in The Androids of Tara while Neil McCarthy, Barnham, returns in the following story to that as Thawn in The Power of Kroll. Roy Purcell, Chief Prison Officer Powers, receives a promotion to the President of the Council of the Time Lords in The Three Doctors, while Eric Mason, playing Senior Prison Officer Green is also CPO Smedley in The Sea Devils.
Fernanda Marlowe appears as Corporal Bell in this story and the next, while the main guest actor in this tale is William Marlowe, as Mailer, who later is seen as Lester in Revenge of the Cybermen. Despite identical surnames the two were not married, contrary to just about every publication on Doctor Who I've ever read saying they were. At the time William Marlowe was married to Catherine Schell, later to find fame as Maya in Space 1999. Then in 1979 he married Kismet Delgado, Roger Delgado's widow.