Trust a show like Doctor Who to film out of sequence – ‘wibbly-wobbly, timey-wimey’ and all that.

Series boss Steven Moffat told Newsbeat that four episodes of the next series are “in the can”, calling new cast addition Pearl Mackie “a breath of fresh air on the TARDIS”.

But most intriguing, Moff revealed that the Doctor Who team has “just started working on the Christmas episode”.

That’s interesting, because the next series is due to launch in 2017 – in April, according to the Twelfth Doctor himself, Peter Capaldi.

So why is December’s festive episode being shot mid-run, when it’s ordinarily filmed ahead of the series?

Whatever the reasoning, don’t panic – it’ll definitely be ready for Christmas, so your annual tradition of watching the special after a boozy roast dinner won’t be affected.

“It’s got a lot of heart, but it’s got a lot of brain too,” Moffat said of the special. “Figure that one out.”

He might just mean that it’s an emotional episode with a particularly tricksy plot – but c’mon, this is Steven Moffat. When is he *ever* so obvious?

Last year’s Christmas episode saw Nardole (Matt Lucas) lose his head, literally, with his noggin held captive within the robot body of King Hydroflax.

With Nardole set to return in series 10, could the reference to “a lot of brain” and “a lot of heart” be a hint as to the character’s mysterious resurrection?

Or… Time Lords have two hearts. Is a return trip to Gallifrey on the cards? Or are we getting a sequel to Tom Baker story ‘The Brain of Morbius’ from 1976?

Alright, so that last one’s a bit of a stretch…