How will David Tennant return to Doctor Who? 5 theories ranked

The 13th Doctor’s last adventure is upon us. On October 23, in the Doctor Who special episode “The Power of the Doctor,” Jodie Whittaker will leave the Time Lord role and be replaced by... who? While Ncuti Gatwa is playing the Doctor in 2023, David Tennant will return for at least one special before Season 14 begins.

So which face will Jodie Whittaker regenerate into? Unlike previous regenerations, things are about to get more than a little timey wimey.

A secret Doctor Who regeneration

Although there was a press screening for “The Power of the Doctor” on October 11, the final regeneration scene was not shown. This means the BBC is keeping this transition a secret, which is very different from how the show has rolled since 2005. After the Who relaunch, David Tennant took over for Christopher Eccleston, and we saw Tennant’s face in Eccleston’s final outing, “The Parting of the Ways.”

Tennant taking over the role wasn’t a secret, and that’s how it's been ever since. The new Doctor is announced well before the incumbent Doctor has their regeneration episode, and then we briefly see both Doctors in the same episode. But now that’s clearly not what’s going to happen. Outgoing showrunner Chris Chibnall has revealed that this regeneration will be “visually very different,” and has strongly implied the regeneration won’t take place in the TARDIS.

David Tennant’s 2023 Doctor Who return

In addition to the announcement that Ncuti Gatwa would become Jodie Whittaker’s successor for next season, returning showrunner Russell T Davies has also revealed that David Tennant and Catherine Tate are returning for three specials that will air in 2023, leading up to the 60th anniversary of Doctor Who on November 23, 2023. This makes it seem like David Tennant’s return as the Doctor will almost certainly happen before we see Ncuti Gatwa as the Doctor, but maybe not.

Tennant played the 10th Doctor from 2005 to 2010, and he returned via time travel for 2013’s 50th anniversary special “The Day of the Doctor.” But this time it appears Tennant is playing a new version of the Doctor, which is where things get interesting. How could Tennant reappear? Let’s break down five theories, getting increasingly wild as we go.

Theory #5. Jodie Whittaker will regenerate into David Tennant

Because Tennant’s comeback is seemingly happening before Gatwa’s Season 14, the leading fan theory is simple: The Doctor’s appearance will revert to an older face of the 10th Doctor. Although this has never been depicted, there is a precedent for a newer Doctor adopting the face and persona of a previous incarnation. In “The Day of the Doctor,” the 11th Doctor (Matt Smith) met a far-future incarnation of themselves called “The Curator,” who was clearly the 4th Doctor (Tom Baker). This version of the Doctor said, “in years to come, you might find yourself revisiting a few [faces].”

This seemed to establish that the Doctor will, for whatever reason, regenerate with an “old” face. So, if in “The Power of the Doctor,” Jodie Whittaker regenerates into David Tennant, that doesn’t mean Tennant is the 10th Doctor again. Instead it means he’s a new version of the Doctor with the memories of Smith, Capaldi, and Whittaker. Got all that?

Theory #4. The Doctor will fracture into multiple Doctors

Because the three 2023 specials are connected to the 60th anniversary celebration, fans have speculated that more previous Doctors may be returning. Although both Matt Smith and Peter Capaldi have been quiet, it’s possible they’re both returning for at least one special. If so, they could be playing different versions of the Doctor who are all spun out of the 13th Doctor via a regeneration that results in several “new” Doctors instead of just one.

This has a sideways precedent too. The 10th Doctor nearly regenerated, but instead created a half-human duplicate of himself. One botched regeneration resulted in two Doctors. Could something similar happen again?

Theory #3. David Tennant is playing the human Doctor

Speaking of the 10th Doctor, the episode “Journey’s End” saw him leave his human duplicate in a parallel universe with Rose Tyler (Billie Piper). A deleted scene showed that this Doctor was given a TARDIS too. So, it’s possible that Tennant’s Doctor in the specials isn’t the “regular” Doctor, but instead the Doctor from that parallel universe. This theory would neatly explain why he looks older; we were told that version of the Doctor would age naturally.

Theory #2. David Tennant is not playing the Doctor

One wild theory suggests that the new Tennant Doctor in the 2023 specials is, in fact, not actually “the Doctor,” but instead a dark regeneration of the Doctor. This evil Time Lord initially comes from the 6th Doctor (Colin Baker) era, but was referenced in the modern era too. In Matt Smith’s “The Name of the Doctor,” it was implied a terrible future version of the Doctor would be given the name The Valeyard.

This feels unlikely, but if true it would mean Tennant isn’t the Doctor exactly, but a villain.

Theory #1. Jodie Whittaker won’t regenerate... yet

We know Jodie Whittaker is leaving Doctor Who. But with the 60th anniversary just around the corner, the wildest possible result of her regeneration scene in “The Power of the Doctor” would be not to regenerate at all. Perhaps what we see in the trailers isn’t her regeneration, but a moment where she gains all the knowledge of her hidden past lives when she worked for the Division.

A fake-out regeneration has happened before, too. In “The Stolen Earth,” the 10th Doctor (Tennant) appeared to regenerate but didn’t. The 12th Doctor (Capaldi) episode, “The Lie of the Land,” also had a fake-out regeneration. Also relevant: The 10th, 11th, and 12th Doctors were all able to delay their regeneration for a significant amount of time before eventually succumbing.

So what if that’s what happens with Jodie Whittaker? We think she’s going to regenerate, but then she stays herself and lives to join forces with whatever’s going on with David Tennant in the specials. If that’s the case, it would be the biggest twist in Who history; a regeneration that leads to the same Doctor teaming up with even more Doctors.

“The Power of the Doctor” airs on BBC and BBC America on Sunday, October 23, 2022.