Theory:Doctor Who television discontinuity and plot holes/Colony in Space


 * 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. Given that TARDISes would return to "fading" after this serial, the depiction here can be seen as an error. Although the TARDIS typically "fades" in and out, this is not always the case. Sometimes by intent, sometimes due to mechanical/pilot error, the effect can appear different. Two examples of differing materialization/de-materialization effects are The Christmas Invasion and The Runaway Bride. 


 * IMC still use tape spools. In Genesis of the Daleks, the Kaleds use Magnetic Tapes, so its not beyond the possibilty that goverments have returned to that medium for storage, much like records/vinyls becoming popular again in the 21st Century in our world. Also, it is strongly implied that the future has become a grim, over-populated place in which resources have to be very carefully managed, in which case it is by no means unlikely that obsolete equipment would be returned to service in lieu of more sophisticated but more expensive alternatives (hence also the use of obsolete firearms).


 * In episode two the monitor screen on board their ship turns bright blue in every close up.


 * The Brigadier is fortunate that when he walks to where the TARDIS vanished and tells it to 'come back at once', that it does so in a different corner of the room.
 * With the exceptions of 'Logopolis' and 'Parting of the Ways', when the TARDIS is being specifically directed to materialize around someone/thing, the TARDIS never materializes around an object or person, or even inside solid matter. It is reasonable to assume that the TARDIS performs some kind of scan of the area it is about to arrive in and thus deflects its exact point of materialization accordingly to avoid causing damage or harm to anyone/thing.


 * Jo's skepticism about the TARDIS being mobile is odd as she saw it dematerialize in the last story.
 * In the short time that she has known him, the Doctor has shown little ability to make it mobile when he wants it to be.


 * If the Master was so ready to kill the Doctor at the end of episode four, why does he use a non-lethal gas when the Doctor goes into his TARDIS? He only learns that the Doctor can guide him into the primitive city after he releases the gas.
 * The Master has shown that he would rather kill the Doctor with a more personal touch. Remote control from a distance away, without being able to gloat about it, would be unexpected.


 * Dent radios Earth referring to his ship as "Survey Ship 43" but the tail is clearly labeled 157.
 * The label refers to some other designation then, such as the model of ship that it is.


 * 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. And why does the Master's alarm use a light beam instead of going off when the door is opened? Besides, given the placement of the beam, it would have been broken until the doors were open. The alarm should have gone off the second the Master closed the doors.
 * He set the system up himself, and somewhat recently (it was not there in Terror of the Autons). He clearly would not set it up so that it went off when he simply closed the door, but only when something breaks the beam from in between the sensors.


 * 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.
 * Having never been on an alien planet personally, it's hard to say that none of them would have ground like that. A flat, rock surface with a shallow layer of sand does not seem unreasonable.


 * In Episode Three, as Winton, pursued by IMC guards, falls at Caldwell's feet, seagulls can be heard.
 * It's quite plausible that the planet has some form of life which sounds similar enough to seagulls.


 * One might question the 'compassion' of the leader of the Uxarieans, as the Doctor calls it. He would have his own people slaughtered without even a warning rather than give the Doomsday weapon to the Master.
 * As indicated, he feels that letting the Master have the weapon would be an unacceptable risk to all life.


 * In Episode Two, why does the Doctor drive the IMC patrol buggy when he's a prisoner? (Apart from the fact that Jon Pertwee fancied doing so on the day of filming!) Over to you...