Part 4

Image for Part 4Not currently available on BBC iPlayer

Duration: 25 minutes

The Doctor and UNIT race to prevent the Master from broadcasting the deadly activation signal and opening the channel for the Nestene's arrival on Earth.

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Doctor Who
Jon Pertwee
Jo Grant
Katy Manning
Brigadier Lethbridge-Stewart
Nicholas Courtney
Captain Mike Yates
Richard Franklin
Sergeant Benton
John Levene
The Master
Roger Delgado
Rex Farrel
Michael Wisher
Radio Telescope Director
Frank Mills
Auton Voice
Haydn Jones
Auton Leader
Pat Gorman
Auton Policeman
Terry Walsh
Barry Letts
Barry Letts
Robert Holmes


Doctor Who Extra: Listen - Watch it Now!

Doctor Who Extra: Listen - Watch it Now!

Peter Capaldi and the team reveal the secrets behind one of the spookiest episodes yet…

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