Episode 1

Series Episode Number: 131

World Premiere: Sat 8 Oct 1966 - 5:52pm BST [BBC One] (United Kingdom)
Running Time: 23 minutes 8 seconds

5.50 Million (UK)

Appreciation Index: 50 (UK)

Chart Position: 77 () (UK)

Recorded on Sat 17 Sep 1966 in Riverside 1
Archive State: 16mm t/r

Landing at the South Pole, the travellers find that Earth's twin planet is disrupting a space mission. The Doctor predicts that they will soon receive visitors from the new planet.

Characters include uncredited
Dr. Who		William Hartnell
General Cutler		Robert Beatty
Dyson		Dudley Jones
Barclay		David Dodimead
Schultz		Alan White
Williams		Earl Cameron
Tito		Shane Shelton
American Sergeant		John Brandon
Polly		Anneke Wills
Ben		Michael Craze
Wigner		Steve Plytas
Radar Technician		Christopher Matthews

Production Team hide uncredited
Writer		Kitt Pedler
Director		Derek Martinus
Producer		Innes Lloyd
Designer		Peter Kindred
Script Editor		Gerry Davis
Title Music		Ron Grainer
Title Music		BBC Radiophone Workshop
Studio Lighting		Howard King (uncredited)
Studio Sound		Adrian Bishop-Lagget (uncredited)
Costume Designer		Sandra Reid (uncredited)
Make-up Designer		Gillian James (uncredited)
Assistant Floor Manager		Jenny McArthur (uncredited)
Production Assistant		Edwina Verner (uncredited)
Vision Mixer		Shirley Coward (uncredited)
Special Sound		Brian Hodgson (uncredited)
Title Music Arranger		Delia Derbyshire (uncredited)
Title Sequence		Bernard Lodge (uncredited)