Theory:Doctor Who television discontinuity and plot holes/Spyfall


 * The Master says he took a trip home to Gallifrey in its "bubble universe," although it is established in Hell Bent that Gallifrey became unfrozen from another dimension and returned to the real universe, though at the extreme end of the time continuum.
 * It is unclear if the Master was aware of it becoming unfrozen so as far as he's concerned, it was still in a bubble universe.