Colony In Space
10 April 1971
Nicholas Courtney (Brigadier Lethbridge-Stewart) [1,6], Roger Delgado (The Master) [4-6], Nicholas Pennell (Winton), John Ringham (Ashe), David Webb (Leeson) , Sheila Grant (Jane Leeson) , Roy Skelton (Norton) [1-4], Helen Worth (Mary Ashe), John Line (Martin) , Mitzi Webster (Mrs. Martin) , Pat Gorman (Primitive and Voice / Primitive) [1-2,4,6]*, John Scott Martin (Robot) [1-3], Peter Forbes-Robertson, John Baker, Graham Leaman (Time Lords) , Bernard Kay (Caldwell) [2-6], Morris Perry (Dent) [2-6], Tony Caunter (Morgan) [2-6], John Herrington (Holden) , Stanley McGeagh (Allen) , Pat Gorman (Long) , John Tordoff (Alec Leeson) , Norman Atkyns (Guardian) [4,6], Roy Heymann (Alien Priest) [4,6], Pat Gorman (Colonist) 
|Written by||Malcolm Hulke|
|Directed by||Michael E Briant|
|Produced by||Barry Letts|
The Time Lords discover that the Master has stolen secret files revealing the location of the dreaded Doomsday Weapon. They summon the Doctor out of his exile on Earth and send him five centuries into the future to the planet Uxarieus to retrieve and safeguard this vital information.
Arriving on Uxarieus, the Doctor and Jo encounter a group of Earth colonists whose very existence is under threat due to failing crops and low morale. Representatives of the ruthless Interplanetary Mining Corporation are disputing the colonists’ claim to the planet.
Their only hope is placed on the imminent arrival of an Adjudicator from Earth to resolve the dispute. Meanwhile, the Doctor pursues his mission, but first he must deal with giant lizards, killer robots, and deadly primitive tribesmen – knowing all the while that the Master cannot be far away.
- The manner of TARDIS dematerialization and rematerialization is quite different to how it had been depicted during the 1960s. Both TARDISes in this story “pop” in and out of frame, rather than fading in and out.
- In episode two the monitor screen on board their ship turns bright blue in every close up.
- Dent radios Earth referring to his ship as “Survey Ship 43” but the tail is clearly labeled 157.
- When Jo and the Doctor are sneaking into the Master’s TARDIS, the Doctor jostles one of the doors that had the alarm beam. This would certainly break the beam.
- When Morgan finds the key to the Master’s TARDIS, the “ground” it is on is a flat concrete floor with a little sand thrown on it.
In Episode Three, as Winton, pursued by IMC guards, falls at Caldwell’s feet, seagulls can be heard.
- The 23rd March 2472 will be a Thursday, not a Tuesday.
- In the last scene of episode six, after the Brigadier has repeated his “come back at once” line, the shadow of a crew member can be seen projected across his front.
- This is the first time since The War Games that the TARDIS traveled to another planet.
- From the Brigadier’s perspective, the Doctor and Jo were only away from UNIT headquarters for a matter of seconds. It is thus the only televised example of
- Rose Tyler’s admonition to her mother in World War Three that the TARDIS is “a time machine. I could go traveling around suns and planets and all the way out to the end of the universe, and by the time I get back, ten seconds would’ve passed. Just ten seconds.”
- This story gives us a glimpse of Time Lords on Gallifrey. Time Lords are again depicted as wearing black and white robes, as they were in The War Games.
- The Doctor and Jo gain entry to the Master’s TARDIS using the key the Doctor obtained in Terror of the Autons. However, the Doctor appears not to have the key at the conclusion of this story.
- This is the first time Jo Grant sees the interior of the Doctor‘s TARDIS. Much of the first half of episode one revolves around Jo’s adjustment to her new status as a time/space traveller. Though having been the Doctor’s companion for some time, she reveals that she never really believed that the Doctor could travel in time and space until this story. Thus, this story has many features of the traditional “first story” for a new companion.
- The Adjudicators are expanded upon in Lucifer Rising and Original Sin.
- The Doctor himself poses as an earth magistrate, the Examiner, on the planet Vulcan in The Power of the Daleks.
- Roger Delgado was credited as "Master" on episode four and "The Master" on episodes five and six.