Theory:Doctor Who television discontinuity and plot holes/The Caves of Androzani


 * It is clear when seeing the Doctor through the eyes of the robot in episode two that he is wearing his hearts on the outside of his jacket.
 * The android is seeing through his jacket except for an outline of it.


 * In one moment of the regeneration scene, the Doctor's head is on Peri's lap, in the next he is lying flat on the floor with Peri nowhere near him.
 * After the regeneration we see her crouched by the door.
 * She moves, likely having been scared by the lights/energy release.


 * When Stotz is firing at Sharaz Jek at the conclusion of part Four, part of his gun splits in two and falls off.
 * Perhaps it's part of the gun's magazine?
 * The gun has been used and fired in a rather inhospitable environment, and we don't know how old and well-maintained it is. It could just simply be broken.


 * Why does Stotz have to kill his crewmates in episode 4?
 * The practical reason is that they could be a liability or threat, as they know him and his immediate plans. He also has a long-standing feud with at least one of them, and appears to enjoy killing them.
 * In all justice to Stotz (as far as he deserves any), there is only one serviceable ship left (Morgus' ship, after the Doctor crash-landed the gun-runner's ship), and Krelper is most unlikely to wait for Morgus and Stotz to return before taking off.
 * Also, he wants to send a message to Morgus not to think about trying to double-cross him.
 * He's a ruthless criminal who wants to keep and profit the incredibly valuable cargo they're there to steal without having to share any of it. He was likely always planning to murder them at some point, and that turned out to be a convenient moment.


 * Why didn't the Doctor quickly drink his half of the bat's milk before returning to Peri? Hindsight aside, surely it would've been easier to get Peri to safety if he hadn't been suffering from the effects of spectrox toxaemia himself.
 * The Doctor wasn't sure how much of the bat's milk would be necessary to cure either of them so he wanted to make sure Peri got enough first. When he got to her with only one tube he told her it was (only) enough for one to reassure her. And maybe he knew it was time for him to regenerate anyway.
 * He also could have inadvertently drank too much out of instinct, or accidentally dropped it, leaving him better off but Peri doomed to a lingering death. He probably doesn't want to risk it until they're both in actual safety.
 * Ultimately though, he's putting Peri's safety and health priority over his own because... well, because he's the Doctor and we'd expect no less of him. It's why he's a heroic figure.


 * The Gunrunners have already been to Jek's base in part 3, as we see. So why in part 4 does Stotz not seem to know where it is? He tells Morgus that Jek's store of Spectrox must be somewhere near cave 26 on yellow level, and then they wander about the caves for a bit until the sound of a motor leads them to Jek's base. Surely it would make much more sense for Stotz to lead them to Jek's base and then either find out from Jek himself where the Spectrox store is or just look around in the immediate vicinity of the base. After all, in part 3 the android brings the gunrunners' Spectrox to them whilst they're in the base,so presumably the store is nearby. The only explanation I can think of is that Stotz just forgot the way to the Base or was blindfolded on the way there.
 * Jek's base is well hidden within dark tunnels, meaning it's almost certainly difficult to find your way there and back even without blindfolds. Assuming they made their way there without blindfolds the first time, Jek perhaps signposted the way for the gunrunners when they were bringing him his supplies, and then had the signposts removed once they left to prevent them from doubling back. On top of which, there's also a major volcanic event occurring, which would make everything unstable and perhaps block off certain routes. They might be trying to find a different way after the regular way had been blocked.