Doctor Who (1963–1989)
3 user 1 critic

The Mind of Evil: Episode Four 

With the Doctor and Jo being held prisoner, the Master convinces Mailer to help him steal the Thunderbolt.


Timothy Combe


Don Houghton (by)




Episode cast overview:
Jon Pertwee ... Dr. Who
Roger Delgado ... The Master
Nicholas Courtney ... Brigadier Lethbridge Stewart
Katy Manning ... Jo Grant
Richard Franklin ... Captain Mike Yates
John Levene ... Sergeant Benton
William Marlowe ... Harry Mailer
Hayden Jones Hayden Jones ... Lenny Vosper (as Haydn Jones)
Michael Sheard ... Dr. Summers
Fernanda Marlowe Fernanda Marlowe ... Corporal Bell
David Calderisi ... Charlie
Bill Matthews Bill Matthews ... Prison Officer
Barry Wade Barry Wade ... Prison Officer
Dave Carter ... Prison Officer
Martin Gordon Martin Gordon ... Prison Officer


With the Doctor and Jo being held prisoner, the Master convinces Mailer to help him steal the Thunderbolt.

Plot Summary | Add Synopsis







Release Date:

20 February 1971 (UK) See more »

Company Credits

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Technical Specs

Sound Mix:




Aspect Ratio:

1.33 : 1
See full technical specs »

Did You Know?


The colour master videotape was wiped by the BBC in the 1970s and although colour versions were sold overseas, only 16mm black-and-white film prints were retained by BBC enterprises. However, this episode was restored to colour for the DVD release in 2013 using the chroma dots discovered in the film prints. See more »

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User Reviews

The Keller machine presents a much greater threat.
11 January 2019 | by Sleepin_DragonSee all my reviews

You have to hand it to whoever it was that designed the Keller machine, and to the writing of Don Houghton, they truly did manage to make that box of living hate come to life, it posed a real threat.

Not much in the way of special effects, buy what is done, is done well, I thought the scenes of the machine retaliating when attacked were particularly good.

I work say this is another strong episode from a very strong story, there is lots of action, and fans of the Pertwee era will I'm sure enjoy the car chases, fight scenes, of which there are plenty.

Shock, horror, the episode ends with the exact same cliffhanger once again. Repetitive much? Who cares, I'm really enjoying Mind of Evil. 8/10

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