The Armageddon Factor (TV story)

Synopsis
The final segment of the Key is traced to the planet Atrios, engaged in a long war with the neighbouring Zeos. The Marshal of Atrios intends a final strike to destroy the Zeons, but the Doctor and Romana discover that Zeos is deserted and the war is being co-ordinated by a computer called Mentalis, built by one of the Doctor's old Time Lord Academy friends, Drax.

The computer is under the control of the Shadow, an agent of the Black Guardian. He and his servants, the Mutes, are inhabiting an unseen third planet positioned between Atrios and Zeos.

The Doctor creates a temporary substitute for the final segment from a substance called chronodyne and uses the Key to place a time loop around the ship from which the Marshal is about to launch his strike against Zeos. It transpires that Atrios's Princess Astra is the real sixth segment. The Shadow converts her into the segment, but the Doctor snatches it and escapes to the TARDIS, where he finally completes the Key.

The White Guardian appears on the scanner screen and congratulates the Doctor. He asks that the Key be given over to him, but the Doctor decides that it is too powerful for any one being to control and orders it to re-disperse.

Enraged, the Guardian reverts to his true colour - Black - and vows that the Doctor shall die for his defiance. In order to shake him off, the Doctor fits a randomiser to the TARDIS's controls. There is now no telling where or when his travels will take him.

Plot
The TARDIS lands on a planet, where the Doctor and Romana conclude their search for the key to time. The Black Guardian poses a threat, but the Doctor foils the Black Guardian's evil schemes. The Princess is the final segment to the key to time.

Cast

 * The Doctor - Tom Baker
 * Romana I - Mary Tamm
 * K-9 - John Leeson
 * Princess Astra of Atrios - Lalla Ward
 * The Black Guardian - Valentine Dyall
 * Drax - Barry Jackson
 * Marshal - John Woodvine
 * The Shadow - William Squire
 * Shapp - Davyd Harries
 * Merak - Ian Saynor
 * Guard - John Cannon
 * Guard - Harry Fielder
 * Technician - Iain Armstrong
 * Pilot - Pat Gorman
 * Hero - Ian Liston
 * Heroine - Susan Skipper

Crew

 * Assistant Floor Manager - Steve Goldie
 * Assistant Floor Manager - Rosemary Padvaiskas
 * Costumes - Michael Burdle
 * Designer - Richard McManan-Smith
 * Make-Up - Ann Briggs
 * Producer - Graham Williams
 * Production Assistant - Ann Aronsohn
 * Production Unit Manager - John Nathan-Turner
 * Script Editor - Anthony Read
 * Special Sounds - Dick Mills
 * Studio Lighting - Mike Jefferies
 * Studio Sound - Richard Chubb
 * Theme Arrangement - Delia Derbyshire
 * Title Music - Ron Grainer
 * Visual Effects - John Horton

Quotes

 * K-9 Optimism - belief that everything will turn out well. Irrational borderig on insane.

Story Notes

 * Originally the sixth segment was to be the Shadow's shadow.

Ratings

 * Part 1 - 7.5 million viewers
 * Part 2 - 8.8 million viewers
 * Part 3 - 7.8 million viewers
 * Part 4 - 8.6 million viewers
 * Part 5 - 8.6 million viewers
 * Part 6 - 9.6 million viewers

Myths
to be added

Filming Locations

 * Filming conduct within BBC studios

Discontinuity, Plot Holes, Errors
to be added

Continuity

 * The Black Guardian reappears in Mawdryn Undead.
 * The Doctor has been shrunk before in Planet of Giants.

DVD, Video and Other Releases
to be added

Target Novelisations

 * Published by Target as Doctor Who and the Armageddon Factor By Terrance Dicks in 1980.