Theory:Doctor Who television discontinuity and plot holes/The Infinite Quest


 * The TARDIS' temporal grace field, previously established as preventing weapons from being fired inside the ship, evidently doesn't work against Baltazar's ray gun.
 * There have been several examples within the series of temporal grace not working, including Earthshock and The Parting of the Ways. The Doctor has indicated that it, like many capabilities of the TARDIS, does not always work the way it's supposed to (Time-Flight) In a future story (TV: Let's Kill Hitler), the Doctor tells Mels (Melody Pond) that it was a clever lie.


 * The sonic screwdriver in the story has a green casing, unlike that used in the television series.
 * Maybe it's possible to change the casing, like mobile phones or iPods.


 * Left unexplained is how Martha, Baltazar and the Doctor are able to breathe and speak outside the Infinite vessel, which is depicted as floating in space. The ship could have an oxygen field keeping the air in, but this may not be true as the ship itself is a wreck.


 * Also not explained is how the Doctor kept from freezing to death during his long voyage atop Squawk.
 * The Doctor has been shown to be able to survive very cold temperatures (TV:Planet of the Ood), and in one Fifth Doctor televised adventure, Four to Doomsday, this has included him withstanding the vacuum of space.


 * There's an issue involving timing. Baltazar steals the TARDIS and Martha and heads straight to the Infinite. The Doctor spends the next three years preparing his rescue and travelling to the Infinite's location (though he's able to trim things down to 2 3/4 years thanks to light speed). How was the Doctor certain that the TARDIS was going to travel three years (or 2 3/4 years) into the future? It could have arrived at the Infinite mere moments after the Doctor was stranded.
 * Presumably the Doctor must have secretly programmed the TARDIS to travel through time to give him enough head-start to plan his rescue. An example of the TARDIS travelling through time without the Doctor is in Revenge of the Cybermen.