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


 * If there are thousands of people on Nerva, why is there only 1 shuttle and a transmat with only 3 pads?
 * The Shuttle may be larger than what we see (note that the entire Wirrn swarm is able to fit aboard it) and there are probably more transmat pads throughout the station. Vira does say that getting everyone down to Earth via transmat will be a long task.


 * Why do they teleport to the Earth rather than take the TARDIS?
 * The TARDIS can be unreliable at times.


 * There is a piece of very poor editing done when the half-mutated Noah confronts Vira and the Doctor as they move along the corridor (probably done to remove the more grotesque aspect of the scene). Noah is still talking and then somehow the door slams shut, cutting him off. Yet it is not clear who does this or what exactly happened.
 * One of the three easily could have pushed the button to seal the door. Vira and the Doctor have a good motive for doing exactly that!


 * The people needed to use a device on their hearts to complete the revival - how would this have worked if no-one was around to help them with it?
 * It's not part of standard procedure; the system had already malfunctioned due to the Wirrn's interference.


 * The Wirrn falling out at the first cliffhanger interrupts the Doctor talking - but he's not talking at the start of episode 2.
 * Or we just don't hear him.


 * When Sarah is trapped in the control room, why is the switch for the door on the opposite side of the room?
 * Why not? All functions for the room are controlled from the console.


 * Once the auto guard has been switched off, the Doctor and Harry test it by sticking their heads out!
 * That's where their eyes were located. They heard it deactivate and were cautiously looking to verify.


 * The slime trail which the Doctor and Harry chance upon is clearly visible to the audience from the start of the scene.
 * The trail was supposed to be there. In the story the Doctor and Harry simply do not see it at the start of the scene.


 * Can all of the Wirrn really fit into that small cockpit?
 * Probably not, but the shuttle is larger than just the cockpit.


 * Why doesn't the Doctor want to wake everybody up and take them to Earth in the TARDIS? His reasons make it sound like he's just making the game more interesting.
 * Using the TARDIS to change events is something he usually shies away from. Plus, the logistical issue of waking them all up and getting them to the TARDIS would be challenging to say the least.
 * He doesn't need to; the Ark has shuttles and teleporters that can send them down to Earth. The Doctor's willing to help with the Wirrn problem, but he's not a taxi-driver.


 * Several of the cyrogenic cells are empty, but there are no slime trails leading to them. With space at a premium it doesn't make sense to have empty cells, but the lack of slime trails means the Wirrn didn't take the bodies either. So where'd they go?
 * They are presumed to have been taken by the Wirrn. The slime trail simply isn't visible.


 * Why is the table screwed down to the floor? None of the other furniture is. Plus as the Doctor and Harry start to move the table there's no mounting in the floor where the screw was.
 * The table was apparently never meant to be moved, hence it was screwed down.


 * It may also be a precaution in case the artificial gravity fails.


 * In the human-preservation chamber there are at least two levels of cells, but there are no ladders. How do the people get down when they wake up?
 * It is just possible that in the future humans have invented the lift.


 * Given how readily the Doctor used his sonic screwdriver as a thermal lance in the previous episode, and how readily it went through reinforced metal, why doesn't he cut a quick hole here to get some air?
 * We don't know the composition of this metal compared to various metals in previous episodes. And if the atmosphere on the other side contains high levels of oxygen, as would be expected, then creating sparks and fire is a bad idea.


 * The space station noticeably "wobbles" as it orbits above Earth in the opening shot.
 * Real space stations do "wobble".
 * Alternatively, the station isn't wobbling, but the perspective looking at the station is. The insect creature who's eyes we're seeing through isn't flying in a straight line, but rather zig-zagging around a bit on the way to the station.
 * Ultimately this is a production error not a plot hole. The space station presumably isn't supposed to wobble, it's just a side-effect of the practical effects and limited budget. You're supposed to just apply willing suspension of disbelief and politely pretend that the space station is floating serenely in space.


 * When Vira climbs out of the cryogenic capsule, the styrofoam comprising the capsule sqeaks.
 * Do cryogenic capsules not normally squeak? Never having been in one from the far future, I can't say...


 * Without space-faring technology, how do the Wirrn launch themselves into space, and how do they avoid burning up during planetfall?
 * While I'm not sure how they reach escape velocity, re-entry could likely be accomplished by spinning a durable chrysalis/cocoon, or a mixture of spun, silken material and debris, similar to the approach of the Caddisfly larvae.
 * When Gary Russell announced he was bringing back the "Wirrrn" (in Placebo Effect), he promised that he'd answer the escape velocity question. But he didn't; all we learned is that usually getting back into space involves sacrificing large numbers of Wirrn to get a few of them out there (which is fine for the why—they are a hive mind—but doesn't help at all for the how), but fortunately for them sometimes they find space-faring races like humans, and they can just have half-converted larvae use human technology (which explains how they did it in that novel, but not in general).
 * When confronted about that on rec.arts.drwho, Russell replied, 'Isn't it obvious? It's the third "R"'.


 * While the suspended humans have been "oversleeping", the rest of humanity has supposedly been branching out across the universe. So how can Nerva simply have been forgotten? Surely someone down on Earth would have noticed.
 * There is no one down on earth, like you said humanity is branching across the universe, the earth has been abandoned, and as shown in the next story, humans by this point think nerva is just a myth, so there is no reason for them to go back, to look at it.


 * If the human race has the technology to travel to other planets, and are even shown to have colonies in other stories, why rely on the Ark or the mentioned thermic shelters for survival rather than simply relocating to another planet?


 * This makes sense within the context of the story, as Vira implies that the humans who fled the doomed Earth to form colonies were not considered likely to succeed (She is immensely surprised to hear that humans made it to Andromeda, and her short exchange with Noah about the "regressive" volunteers for "Colony 9" and their low odds of success reinforces this pessimism). Within the wider context of the show, of course, it makes far less sense. "The Mutants" (30th century), "Colony in Space" (25th century), "The Sensorites" (28th century), "Frontier in Space" (26th century), and "Terror of the Vervoids" (30th century again) all depict aggressively colonial and competently space-faring humans either before or contemporaneously with the Nerva pioneers. Having said that, "The Mutants" does at least imply that Earth's first galactic empire collapsed pretty abysmally, for reasons undisclosed, and forced the remnants of humanity to return to an already pretty well screwed-up Earth. The news of imminent solar flares must have come as a delightful surprise to them after that... The "regressives" that Vira and Noah refer to could have been those humans who took the solar flares as a sign that the Marshal had been right all along, and hopped right on the first clapped-out old colony ship back to Solos.


 * Retconning has attempted to resolve this by placing only Nerva's construction date in the 30th century ("Revenge of the Cybermen" complicates the issue even in the same season)), while placing the solar flares and the Ark at a substantially later date. This would at least explain why the stilted speech and mannerisms of the Nerva personnel have nothing much in common with other 30th century humans in the show (as in "The Mutants" and "Terror of the Vervoids"). The Doctor seems quite positive that Vira is a typical example of a 30th century medtech, but there is no reason why the Doctor has to be right every time...


 * Simple contingency measures. The old saying about eggs and a single basket comes to mind. If all of humanity relocates to another planet, and that planet turns out to not be as survivable as assumed or something unexpected happens, then all of humanity is dead. Relying on the Ark, the thermic shelters and interstellar colonisation means that if one survival plan fails, humanity continues to survive somewhere else, or at least has a better chance of doing so.


 * One major plot hole seems to be this; given that the humans on the Ark have overslept by approximately five thousand years, this means that the Queen Wirrn must have entered the Ark, sabotaged its 'alarm clock' and other systems, laid the egg sack inside Dune and been killed by the auto-sentry five thousand years prior to the events of this story taking place. However it is fairly obvious that the egg sack laid inside Dune has only just started making its way toward the solar stack as the Doctor and his companions arrive. Why then has it taken five thousand years from the Queen laying her eggs to the sack being ready to hatch-out? A slow reproductive cycle seems an unlikely explanation given the speed at which the Wirrn develop once the egg sack reaches the solar stack.
 * Possibly it went overboard in sabotaging the cables, and crippled the entire power system. The Doctor later indicates that the solar stack can be operated from the control room. Until Nerva was reactivated by the Doctor, it may have been that the Wirrn larvae were as much in suspended animation as the sleepers, until the power started flowing again...