(For those who’d rather read the theory, see below).

After letting the news of a potential, err, 16th incarnation of the Doctor gestate for a bit, I can succinctly say I’m thoroughly confused and not yet on-board. You see, I’ve been playing out every scenario in my mind as to where Jo Martin’s Doctor could fit, and I can think of only 7 potential solutions, all of which feel very wrong to me, but some less than others. In this editorial we’ll break down everything we know about the so-called ‘Ruth Doctor,’ the entire mythos surrounding the Doctor, explain the 12 regeneration limit, and every possible point the Ruth Doctor could feasibly, albeit flimsily, fit onto the muddled and hectic Doctor Who Timeline.

So what do we know of Ruth Clayton? First and foremost we are privileged to the fact that she used the Chameleon Arch, first introduced in the Tenth Doctor 2-parter, Human Nature and The Family of Blood, where The Doctor used the device to modify his biology to become human so as to hide for a period undetected. The Chameleon Arch is the same mechanism The Doctor uses in Fugitive of the Judoon to hide away on earth for an unknown period of time, under the guise of being a tour guide in Gloucester, named Ruth Clayton, equipped with a nice necklace in the shape of an R. Instead of hiding her Time Lord essence in a fob watch as 10 did, she hid her’s behind a glass pane at an abandoned lighthouse.

Unlike the 10th Doctor, who due to time-period constraints could use Martha in no other capacity than as a house servant, Ruth’s companion, Lee Clayton, took on the title as husband. He was, according to Gat, a faithful companion, and likely not the intergalactic criminal we are led to believe he is.

The Ruth Doctor, as we’ll have to call her until the position is clarified, claims to be one of the 13th Doctor’s past incarnations, but considering neither Doctor remembers the other, it can’t be ruled out that she isn’t a future iteration of the Doctor. But there are several reasons to believe her, one of which being the internal and external state of the TARDIS appearing like a modernized version of some of the earlier TARDIS consoles from Classic Who, as well as the fact that she doesn’t know what a Sonic Screwdriver is, and both of those points are very important. More on that in a bit. We’ll cross off the possibility of her being a future incarnation for now.

So what do we know about the Doctor? We’ve seen him at his youngest in the 8th Series episode, Listen, where Clara visits the place where he as a young boy grew up. This is likely while he’s still a normal Gallifreyan, before he looks upon the Untempered Schism, and goes into the Academy, becoming a Time Lord. So we can surmise that as a normal Gallifreyan, he does not yet have the ability to regenerate, and is, in his earliest form, a male of his species. While we don’t truly know if this young Gallifreyan boy will grow up to become the First Doctor as we know him as from the first four seasons of the show, between 1963 and 1966, there is a bit of in-universe evidence to suggest that William Hartnell may not have been the first incarnation of the Time Lord.

In the final episode of the Fourth Doctor story the Brain of Morbius, the Doctor challenges Morbius to a mindbending contest, where we see all the previous faces of the Doctor in descending order (Baker, Pertwee, Troughton, and Hartnell), as well as 8 other faces. Fans have debated over this episode for years claiming that these faces were either intended to be previous iterations of the Doctor, or that they were in fact faces used by Morbius, who was also a renegade Time Lord. I tend to believe that they were faces of Morbius, considering the Twelve Regeneration limit being met by Matt Smith’s era of the Doctor. However, as the Time Lords were able to grant the Doctor another cycle of regenerations in the Time of the Doctor, is it now possible to conclude that there could have been a cycle of regenerations prior to the first regeneration we saw, and that William Hartnell’s first Doctor was actually the final regeneration in that cycle? Well, sure. Anything’s possible in Doctor Who, but it’s unlikely, and confusing, and it’s not a route I think any fan wants to go down. So while Ruth’s Doctor COULD be a pre-Hartnell Doctor, it’s unlikely, and the reason being is due to her use of the TARDIS itself.

We have a pretty strong grasp on the TARDIS. As a Type 40, of which only 305 were created, the First Doctor and his granddaughter Susan stole one of them, as seen in the Name of the Doctor. It is explained in the very first episode of the series, An Unearthly Child, that the TARDIS’ Chameleon circuit got stuck and the TARDIS’ appearance would remain a 20th Century English Police Box. The Ruth Doctor’s TARDIS exterior appears much like the first couple Doctor’s TARDISes did, with the square framed lamp at the top, as opposed to the cylindrical one we have on more modern TARDISes. Considering it’s already stuck as a Police Box, and it got stuck that way during Hartnell’s run as the Doctor, it’s a safe conclusion to make that her incarnation does not occur before the First Doctor.

Before we can break down our two prevailing theories, it’s important we discuss our initial thought. Most of us, considering the regeneration limit and the fact that we can account for each incarnation, concluded that this must be an alternate universe Doctor. This theory is aided by the inclusion of the other Time Lord, Gat, who isn’t familiar with Gallifrey being destroyed. However, speaking to Mirror, showrunner Chris Chibnall claimed “she is definitively the Doctor. There’s not a sort of parallel universe going on, there’s no tricks.” So there’s that.

But let’s get back to the 12 regeneration limit. It was originally developed into Doctor Who lore in The Deadly Assassin as the limit a Time Lord is given for regenerations. That means there’s 12 transitionary periods between Doctors, so 13 incarnations total, beginning with William Hartnell’s First Doctor. We know that the regeneration limit was met with the 11th Doctor, which is confusing, but we’ll explain shortly. The limit, as we mentioned earlier, was extended by the Time Lords in the Doctor’s case, which allowed for the Twelfth and Thirteenth Doctors to be possible.

So if Ruth isn’t after the Thirteenth Doctor, isn’t before the First Doctor, nor is she a parallel universe Doctor, it stands to reason she fits between one of the regenerations, or in stead of a current incarnation. To be thorough, let’s break down all of the regenerations that we’ve seen on screen so far, and infer potential gaps in the storytelling that Ruth’s Doctor could fit.

The first regeneration from William Hartnell’s First Doctor and Patrick Troughton’s Second Doctor is directly witnessed in both the final episode of The Tenth Planet, and was recreated again in Twice Upon a Time. Jon Pertwee’s Third Doctor regenerates into Tom Baker’s Fourth Doctor in the final part of Planet of the Spiders. Tom Baker regenerates into Peter Davison’s Fifth Doctor in Logopolis. Interestingly we also get an in-between regeneration here called the Watcher that exists somewhat incorporeally, but I highly doubt Ruth’s Doctor has anything to do with that character, as it joined into the regeneration. The Fifth Doctor regenerated again in the Caves of Androzani, which introduced Colin Baker as the Sixth Doctor. Colin Baker quit before he could film his regeneration, but through the power of TV Magic the regeneration was created using Sylvester McCoy as both a lookalike Sixth Doctor, and a unique Seventh Doctor. After 26 seasons, Doctor Who was shelved for over 6 years, until the TV Movie was released featuring the regeneration of McCoy’s Seventh Doctor and Paul McGann’s Eighth Doctor. One of the bigger tragedies of Who history boils down to the fact that we never got so see any more of McGann than we did in his sole appearance. That is until we saw a mini episode produced in conjunction with the 50th anniversary of the program called the Night of the Doctor, where Paul McGann’s Eighth Doctor became the War Doctor, played by John Hurt. As his was a secret, suppressed incarnation that chose not to call himself the Doctor, he is still counted as an eighth regeneration, but not exactly a numbered Doctor. Now here’s where the regenerations start getting iffy.

At the end of the Day of the Doctor we see John Hurt’s War Doctor begin his regeneration, having finally accepted his title as the Doctor, but we don’t truly get to see a full regeneration like we have with the previous ones we showcased. Note that it’s presumed he regenerates into the Ninth Doctor, as played by Christopher Eccleston, and the story narratively fits with the beginning of Rose, being the Ninth Doctor’s first full story, but we never truly see that full regeneration between the War Doctor and Nine. It’s possible that there could be another hidden incarnation between War and Nine, but we find it unlikely, and we hit that 12 regeneration wall limit again. While Ruth could potentially fit here, it’s hard to believe the Doctor forgot two regenerations in a row, but if they choose to not count the metacrisis Doctor regeneration, it might work. We’ll talk more on that in a bit.

At the end of his first season, in The Parting of the Ways, Eccleston‘s Ninth Doctor regenerates into David Tennant’s Tenth Doctor for the Doctor’s tenth regeneration. The eleventh regeneration, however, is the Doctor’s most confusing. Let’s break it down. In The Christmas Invasion, the newly regenerated Tenth Doctor gets his hand chopped off by the Sycorax. Captain Jack finds and later returns the hand to the Doctor in Utopia. The Tenth Doctor is hit by a Dalek gunstick, triggering his Eleventh regeneration. The Doctor healed the damage to his own body using regeneration energy and aborted the remaining regeneration energy into the hand, a bio-matching receptacle, which allowed the Doctor to regenerate without changing his appearance. The hand, taking the rest of the regeneration energy that would have been used to normally change the Doctor’s appearance, became a human/Time Lord hybrid, and thus meant that the Doctor used up an eleventh regeneration.

This was counted as one of the twelve regenerations, according to the Eleventh Doctor in the Time of the Doctor. Unless they retcon this regeneration’s weight in the numbering, which I doubt they will, the Doctor can’t feasibly have any more hidden regenerations. And it’s impossible that Ruth’s Doctor is the metacrisis Doctor that was banished to Pete’s World, as that Doctor has no regenerative abilities.

The Tenth Doctor, now occupying both the Tenth and Eleventh regenerations, gave up his final twelfth regeneration to the Eleventh Doctor in the End of Time Part 2, as played by Matt Smith.

The Time Lords granted the Doctor a new regeneration cycle, presumably of 12, in The Time of the Doctor. Here, Matt Smith’s Eleventh Doctor regenerated into Peter Capaldi’s Twelfth Doctor, the thirteenth regeneration, or the 1st in a new regenerative cycle. The Doctor again regenerated into the Thirteenth Doctor, played by Jodie Whittaker, in Twice Upon a Time.

Now, that’s most of the regenerations accounted for as being direct face to face swaps. We have 1-2, 3-4, 4-5, 5-6, 6-7, 7-8, 8-War, War-someone, 9-10, 10-10, 10-11, 11-12, and 12-13. But there’s still two unique places I feel Ruth can fit. Maybe you caught one of them already.

We neglected to discuss the regeneration between the Second and Third Doctors. What’s unique about this transition is that we don’t see Jon Pertwee emerge from Patrick Troughton’s face. In fact, at the end of the 10th episode of The War Games, we see the Second Doctor taken into custody by the Time Lords and sent to exile on earth in the 20th Century, but not before changing his appearance. We see the supposed regeneration begin to take effect, but it is never once called a regeneration, nor does it suppose that this Doctor’s life will have ended. They simply claim, “the Time has come for you to change your appearance, Doctor, and begin your exile.” The next we see of the Doctor, he stumbles out of the TARDIS a new man in the next episode, Spearhead from Space, as the Third Doctor, played by Jon Pertwee. As the Time Lords promise, the secret of the TARDIS is removed from him, and he doesn’t have access to it for much of the Third Doctor’s run.

But what if the Ruth Doctor fit between 2 and 3? It’s possible. The TARDIS profile and interior fit the time period. She’s on the run from someone or a group of someones, and Gat, a Time Lord herself, claims to receive her orders from way up. In the War Games his exile is treated as both a punishment and an undefined job of sorts, as they claim that they’ve accepted his plea that there is evil in the universe and the Doctor still has a part to play in that battle. We assume that there must be a regeneration wasted by shoving Jo Martin’s Ruth Doctor in there somehow. But what if she isn’t her own regeneration? Sure, it’s possible the Time Lords could have gifted the Doctor another regeneration, though by the Deadly Assassin time period, there doesn’t appear to be any way for the Time Lords to do that yet, so that’s unlikely. What if they merely changed the second Doctor’s appearance? Instead of being called an in-between Doctor, what if Ruth’s Doctor was still the Second Doctor, just with a different face? I think that’s the most likely solution for fitting the character in in a way that narratively makes sense and doesn’t flub the regeneration cycle any. This theory assumes she’s essentially Doctor 2B.

This does cause some problems, and isn’t foolproof. The Third Doctor stumbled out of the TARDIS with the Second Doctor’s clothing. And we see Jo Martin’s Doctor wearing something wholly different here. She also seems unaware, or disgusted by the use of a sonic screwdriver, when it was the Second Doctor that originally used the sonic screwdriver. So not a perfect fit, but better than most.

There is one final theory I’d like to postulate however. In the Sixth Doctor story, The Trial of a Time Lord, we are introduced to an offshoot version of the Doctor, known as the Valeyard. This is said to be an amalgamation of all the evil within the Doctor and was created somewhere between the Twelfth and Final incarnations, so between the 11th and 12th regenerations. Notice at the very start of the episode we see Ruth looking at her watch, biting her lip with some level of apparent anxiety. Note that the minute hand is about to strike 12, and the seconds slow down just before that occurs. Could this be a clue as to an incarnation of the Doctor, like the Valeyard, between the 11th and 12th regenerations? The Valeyard was known to change his appearance depending on the setting. And on occasion in Doctor Who books and audiodramas the Valeyard claims to work for or have been created by the Time Lords, another reason why Ruth may be on the run.

Is the Ruth Doctor an extension of the Second Doctor? Is she a version of the Valeyard? Is she something else entirely? Let me know your thoughts, and please, please, please help us by sharing this post on Twitter, Facebook, Reddit, or anywhere! Thanks for reading. Have a good one.