Tonight sees the penultimate episode of this season of Doctor Who – Ascension Of The Cybermen, ahead of next weekend's The Timeless Children. Big things are expected, a return of The Master, of the Fugitive Doctor, what happened with Gallifrey, why the Master said everything the Doctor believed was a lie, what the Lone Cybermen was doing, who was sent back in time by the Alliance, and much more. But is there something even bigger coming? Bleeding Cool reader John Joshua noticed that the Saturday before The Timeless Children, BBC One has a "no listings available" half-hour slot in their schedules at 6pm.

This is the kind of slot that the BBC used to announce that both Matt Smith and Peter Capaldi would be playing the Doctor. It is also notable that showrunner Chris Chibnall has gone out of his way to successfully keep some stuff secret this season, including the return of the Master and the identity of the Sacha Dhawan playing him, the return of John Barrowman as Captain Jack Harkness, the appearance of the Jo Martin Fugitive Doctor – could Jodie Whittaker have been utterly lying about returning for a third year as The Doctor? Could we be about to get a regeneration? Either tonight or next week? With that half-hour being used to preempt the change, or promote a Jo Martin Doctor episode to end the season? Could such a thing even be possible?

It's worth noting that this is what Russell T Davies planned with David Tennant originally, a surprise regeneration, until the BBC went and leaked that Christopher Eccleston was only doing one year. So, as we said, this is all Mindless Speculation. But then again, isn't it always?

UPDATE: Nope. Celebrity Mastermind has now filled the slot. No Whodini II. Still it was a fun one, wasn't it?