After months of uncertainty we now know that John Simm is returning to BBC sci-fi series Doctor Who in next week’s episode. The erstwhile villain – who last appeared in 2010 episode The End of Time Part 2 – will make his comeback as The Master in Steven Moffat’s World Enough and Time. He loves those Time titles, eh?

A new trailer has given us our latest glimpse of Simm’s returning baddie (sporting greyer hair and a new goatee since we saw him last, as you can see in the main image) asking an unknown character to “give us a kiss” and we’ve already heard that his chemistry with Michelle Gomez’s Missy is “hilarious” and “gorgeous” – but how exactly is his version of The Master able to make a comeback, what are his plans and what will this whole thing mean for Doctor Who as a whole?

Well, while for now most of the details surrounding Simm’s comeback remain a mystery, we can make a few educated guesses, especially when it comes to the manner of his return. When it was first announced that he’d be coming back, Simm said it was “thanks to the power of time travel,” suggesting that he’d be journeying from some other point in history to join the adventure.

Now, of course this is a fairly obvious point to make – Peter Capaldi's Doctor is currently hanging out with a later version of The Master (Michelle Gomez’s Missy), so there’d have to be some time travel shenanigans involved for Simm to be able to interact with their timeline – but it does raise the question as to when exactly the Master is travelling from.

John Simm's Master clashes with Timothy Dalton's Rassilon and David Tennant's Tenth Doctor in 2010

The last time we saw Simm’s incarnation he was trapped in a dying body and transported to the darkest days of the Time War (see clip above), and the next time The Master was seen at all he had already regenerated into his later female form, Missy (Gomez). This seemed to suggest, then, that the version of Simm’s Master in series 10 would be travelling from a later point in his personal timeline, after his disappearance in The End of Time but before his regeneration into Missy, a hypothesis that seems to have been confirmed by Simm’s brief appearances in new trailers for the series.

Gone is the bottle-blonde hair and scraggly stubble, replaced by greyer cropped locks and a carefully manicured goatee (in keeping with the character’s classic appearances), and while there’s no word on whether this Master will have the same issues he had in The End of Time (where a botched resurrection following his death in an earlier episode left him leaking energy and forced to feed on others) it seems clear that this is a post-Time War version rejoining the action. 

The manner of his escape from the Time War is fairly simple – various incarnations of the Doctor freed Gallifrey and the Time Lords from the war in 2013 special The Day of the Doctor, and that would have included the Master – and if this is Simm’s Master later in his life it also allows for the possibility of a gap-filling regeneration sequence showing exactly how he turned into Gomez’s female incarnation. Lovely, lovely fan-service.

However, it’s less clear exactly what The Master has planned for the Doctor and company. It seems fairly likely that he’ll have something to do with the returning Mondasian Cybermen already confirmed to be starring in the two-part finale, with the latest trailer clip showing him in loose clothing reminiscent of other pre-conversion Cybermen glimpsed in the same preview footage. Maybe he’s undercover waiting to spring a surprise; who knows?

 

Michelle Gomez as a later version of Simm's character, aka Missy

But it would also make sense for Simm’s return to have a connection to his successor in the Master role. After all, the main story thread of this series has been the redemption of Michelle Gomez’s Missy and her turn away from The Master’s traditionally evil side which, judging by the trailer, will be foregrounded even more in next week’s episode. Perhaps Simm’s Master has smuggled himself aboard the spaceship Missy is saving to remind his later self of their true nature – intense, somewhat over-complicated evil – and tempt her back to the dark side, capping off Missy’s story arc as she returns to her old ways despite all the Doctor’s training.

Or maybe he and his later self will find themselves at odds, with Missy sticking by Peter Capaldi’s Doctor against her old self and his massed Cybermen army as he enacts whatever dastardly plan he has in mind.

Peter Capaldi's Twelfth Doctor and the returning Mondasian Cybermen

Whatever the truth, the finished result will be a truly momentous couple of Doctor Who episodes (with Simm expected to only briefly appear in episode 11 before a larger role in series finale The Doctor Falls), marking the first ever multi-Master television story. Over the years there have been plenty of tales where different incarnations of the Doctor have teamed up (including the aforementioned Day of the Doctor and classic episodes The Three Doctors, The Five Doctors and the Two Doctors among others) and a recent audio play where two versions of the Master joined forces (played by Alex McQueen and classic series actor Geoffrey Beevers for Big Finish), but World Enough and Time/The Doctor Falls will be the first time different Masters have shared the screen.

In other words, it’ll be a real milestone and series high for Gomez, Capaldi and showrunner Steven Moffat to depart Doctor Who on when they all leave this year. Assuming, of course, they don’t do a John Simm and surprise us all with a comeback seven years from now…

Doctor Who continues on BBC1 on Saturday 24th June at 6:45pm