Theory:Doctor Who television discontinuity and plot holes/Empress of Mars


 * We never do find out exactly why the Doctor, Bill and Nardole are at NASA in the first place. It is not because of the message being found (which would make the rest of the episode a flashback) as it's clearly indicated they went to Mars to investigate its origin.
 * It's not exactly a plot hole for the story, they likely were just wandering round as the Doctor always does when he's off on adventures.
 * I think it's that the Doctor has already had the adventure, and has gone forward in time to mischeviously see what humanity makes of what he's done.


 * Why does the TARDIS just abandon the Doctor and Bill on Mars? It's not like there's an outward force controlling it like the Silence once did or that it shifted into another dimension like in the Pirate episode.
 * Hostile Action Displacement System, perhaps?
 * And since the TARDIS isn't on Mars for most of the episode, how can they understand the Empress and her Ice Warriors? The soldiers have probably taught 'Friday' English, I suppose.


 * How were they able to move all those rocks, at the end? (Hope this doesn't get deleted!)
 * I guess the super-strong Ice Warriors were able to move them.
 * They are not seen on screen at the time. And, how would the Ice Warriors breath on the surface of Mars?


 * What happened to all the other soldiers that survived? Why weren't they allowed to return home?


 * Where did the fuel for the fires in the tunnels come from?