Doctor Who: just who is in the vault?

Is the person in the Vault in Doctor Who series 10 really who we all think it is? Speculation ahead...

This article contains spoilers up to and including The Pyramid At The End Of The World (we’ve not seen beyond that at the time of writing).

We also talk about someone known to be returning, whose appearance has been revealed in promotions for the show. Still, scroll below the spoiler-squirrel at your peril…

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As Steven Moffat has admitted, it’s the ultimate simple mystery: a locked door, and the question of just who is behind it? And by the end of The Pyramid At The End Of The World, seven episodes into Doctor Who series 10, it seemed as though we’d had our answers. Missy was in the vault. It was all set up thousands of years ago. Mystery solved. Easy peasy.

But, but, but: is that really the answer? Quite probably, but I can’t be alone in wondering if Steven Moffat has something else up his sleeve. Thus, as it’s Wednesday, let’s stop for a game of speculation. Leave polite ridicule in the comments…


The obvious candidate is that Missy is in there. In fact, the Doctor clearly thinks that Missy is in there, and has been talking to her through the door. Following the chronology of the show, he’s also been into the vault, taken some takeaway food, put a piano in: if he’s saying Missy’s name through the door, having been seen to have gone into the vault several times, then you’d have to say Missy is the clear and running favourite.

And yet. There are just a few things that throw doubt on this. We’re half-way through a series after all, and there are still lots more mysteries to unbox here.

Furthermore, we see Missy whacked by bolts, and the Doctor making an oath to guard the body for 1000 years. What we don’t get is just when this is all taking place. The card at the side of Extremis simply tells us this all took place “a long time ago”, and that in itself gives Steven Moffat and his team wiggle room. What if, then, it took place 3000 years ago? 2000? Even 1001? The Doctor has pledged to guard the vault for 1000 years, but we don’t know when those 1000 years were.

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Thanks to The Sun using spoilers as click currency, and the decision by the Doctor Who team to tease his return in the first place, pretty much every Who fan knows that John Simm is returning to the show this series. The assumption, and it’s not an unreasonable one, is that he’ll be back as The Master. That we’ve had The Three Doctors, The Five Doctors, The Two Doctors and Day Of The Doctor. Now, it looks like we’ll get The Two Masters too. 

It’s an inevitable dose of speculation then that in the vault is The Master, but not in the guise the Doctor is expecting. In fact, given that Michelle Gomez has indicated that her time on Doctor Who will be done at the end of this series, might we see a regeneration? The Doctor already outlined that one of the signs of regeneration is hunger, and thus we saw him taking a takeaway into the vault, that most assumed was down to Capaldi’s upcoming exit. But what it he knows that the Master is in there, and about to regenerate? In fact, what if, in the timeline of The Master, Missy is actually an earlier regeneration of the character than John Simm? Could there be a War Master, even? Do we think about stuff like this too much, and do we need a good lie down? 


Going back to the days of the Pandorica, the last time Doctor Who presented us with a long-running what’s-in-there-style mystery, the answer was before us all the time. Steven Moffat has earned good mileage out of keeping his clues hidden more in plain sight and more straightforward that we sometimes recall (remember who The Impossible Astronaut was revealed to be). Therefore, if you factor in that inside the vault is someone the Doctor likes spending time with, and who fancies a takeaway, he’s got to be on the candidate list. Further to that…


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Ah, now here’s the fun theory doing the rounds. Inside the vault is: The Doctor! The new one, more to the point. The working logic here would be that the new Doctor – the replacement for Peter Capaldi – has already been cast. That we’re going to get a surprise as Kris Marshall/Phoebe Waller-Bridge/Richard E Grant/Boris Johnson/Justin Bieber/Harold pops out with their sonic screwdriver, ready to explore the universe for the next few years.

Steven Moffat has been adamant that incoming showrunner Chris Chibnall is writing the first dialogue for the next Doctor, so he’d need sign off on it. Given that revealing the new Doctor early would potentially lessen the impact of the Christmas special, though, we’d be genuinely amazed if this proved to be the case.



There’s a strong rumour that David Bradley will be appearing in the upcoming Doctor Who Christmas special, Steven Moffat’s final episode as Who showrunner. And that rumour centres on Bradley playing the first Doctor. He previously, after all, played William Hartnell, in turn playing the Doctor, in the wonderful An Adventure In Space And Time, and whilst we’ve had no confirmation, a return is looking very likely.

That doesn’t, of course, mean that he’s in the vault. But it certainly increases the possibility of that being the case.


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Let’s go out on a little bit more of a limb here. Go back to the first episode of the series, The Pilot. Remember those photos of the Doctor’s granddaughter, Susan, and River Song, on the Doctor’s desk? If I’ve learned one thing from watching Line Of Duty this past series it’s that cameras don’t linger on things for no reason. As such, when Bill was being discussed, the camera did indeed specifically seem to focus on the image of Susan.

So then: what’s the link? Was it just a couple of pictures on the Doctor’s desk at work? Or, given the theory surrounding the return of the first Doctor, could Susan have a link to it? I’m not convinced she and/or River are in there, but I still wonder if there’s something there.


Again, through the power of teaser trailers and promo shots, we know that the Cyberman are returning to Doctor Who for the end of the series. Not just any Cybermen, either: the Mondassian cybermen, Peter Capaldi’s favourites, from The Tenth Planet.

We don’t believe they’re the answer to the vault mystery, at least not directly, but might it be them?

One thing worth noting: we still don’t know exactly who passed the death sentence on Missy, that the Doctor was supposed to oversee. Could whoever that is yet have a part to play in this all?

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Could the vault be a red herring? Could it, by the time the Doctor opens it, have nobody in it? Nothing would make comments boards on the internet calmer than if the whole thing was a ruse….

We suspect we’ll know a lot more by the weekend. Leave your own thoughts in the comments….