This Doctor Who article contains spoilers for The Power of the Doctor.
Quite a few Daleks, Cybermen, the Master/Rasputin, and volcanic eruptions later, the Doctor has saved the day once again in “The Power of the Doctor,” but it’s not without consequences. In one last evil act, just as the Doctor sets the Quoronx free, the Master makes sure that the Time Lord receives a fatal dose of energy from the space jellyfish, triggering her next, life-altering regeneration.
We all knew this was coming, as the BBC Centenary Special was always meant to be Jodie Whittaker‘s final adventure in the TARDIS. Her inevitable demise at the end of the episode was designed to make way for the next Doctor. And indeed, the final minutes of the special play out exactly how we all expected…mostly. One last goodbye from the Doctor, a few final words (“Tag, you’re it!”) from Thirteen, and then the violent transformation begins — which notably happens outside the TARDIS, breaking with the NuWho tradition of regenerations happening inside the time-traveling police box.
But then the completely unexpected happens. As Whittaker makes way for the Fourteenth Doctor, but it’s not who we thought it would be. Although Ncuti Gatwa (Sex Education) was previously confirmed as the next Doctor by the BBC, it’s none other than David Tennant who takes over for Whittaker in the final seconds of the episode. What? What?! WHAT?!
Now, if you spotted the set photos that made their way to social media platforms earlier this year, you already knew Tennant’s Tenth Doctor would be back for the Doctor Who 60th Anniversary Specials next year, and running around with a few other familiar faces, including Catherine Tate’s Donna Noble. But most fans likely assumed that we’d see Ten running alongside Gatwa’s Fourteen to guide this new version of the Time Lord.
Yet, since the big regeneration twist last night, we’ve also learned a very interesting tidbit about Tennant’s new/old Doctor from returning showrunner Russell T. Davies. Not only is Tennant’s version of the Doctor back, but he’s actually confirmed to be playing the FOURTEENTH Doctor. That means that when Tennant arrives in “The Power of the Doctor,” we’re getting a Doctor who is both the Ten we know and loved as well as the all-new Fourteen.
Where does this leave Gatwa’s Doctor, though? Davies has confirmed that he will officially become the Fifteenth Doctor.
“If you thought the appearance of David Tennant was a shock, we’ve got plenty more surprises on the way!” Davies said in a statement after the episode. “The path to Ncuti’s Fifteenth Doctor is laden with mystery, horror, robots, puppets, danger and fun! And how is it connected to the return of the wonderful Donna Noble? How, what, why? We’re giving you a year to speculate, and then all hell lets loose!”
So, while new incumbents have traditionally followed one another in sequential order in terms of the official numbering — from the very first Time Lord played by William Hartnell to Whittaker’s Thirteenth — Tennant’s return as both Ten and Fourteen breaks that rule. The next time we meet a new actor in the role of the Doctor won’t be Fourteen but Fifteen.
Tennant’s Ten and Fourteen is hardly the first time Doctor Who has abandoned the tidiness of the way Doctors are usually numbered, though. John Hurt’s War Doctor, for example, existed between Paul McGann’s Eighth and Christopher Eccleston’s Ninth Doctors, but a few Steven Moffat-y reasons make it so he doesn’t actually get included in that main numbering. Departing showrunner Chris Chibnall‘s own “Timeless Child” mystery and the introduction of Jo Martin’s Fugitive Doctor (one of the few bright spots of Chibnall’s run, in this writer’s opinion) further fudged the numbers. Throw in all that Valeyard business from the ’80s if you’d like to make things really confusing for yourself.
It’s important to note that past Doctors have a long history of making grand returns for big TV specials — Tennant himself came back for “The Day of the Doctor” in 2013 to ham it up alongside Matt Smith, who was the incumbent at the time — but not usually as part of the actual regeneration cycle. Interestingly enough, the Tenth Doctor has always had a knack for playing fast and loose with the rules of regeneration, such as when he used his severed hand to halt his transformation in “Journey’s End.” Ten is the Doctor who didn’t want to go when his time was finally up, so it makes sense that he’s the one who’s breaking the rules again now.
What exactly this all means for the future of the Doctor beyond the tweaks to the numbering, and how Gatwa’s Doctor will finally enter the scene, are questions we’ll be obsessively asking ourselves until the three-part 60th Anniversary special finally arrives in November 2023.