How does the Thirteenth Doctor die? Jodie Whittaker’s ‘Doctor Who’ regeneration, explained

Warning: This article contains spoilers for Doctor Who: “The Power of the Doctor.”

The Doctor is dead… Long live the Doctor!

Doctor Who reached the end of another era with the release of “The Power of the Doctor”, the feature-length finale for Jodie Whittaker’s Thirteenth Doctor, and what a finale it was. We were promised a truly fan-pleasing experience beforehand, and it’s safe to say the makers of Doctor Who definitely delivered on that. Not only were the Time Lord’s three biggest enemies — the Daleks, the Cybermen, and the Master (Sacha Dhawan) — on display, there were various surprise cameos to keep viewers on their toes.

We all knew how this episode was going to end, with the death, and rebirth, of the Doctor herself. So how did the time traveler’s latest regeneration go down? Let’s find out…

The Thirteenth Doctor’s demise, deconstructed

“The Power of the Doctor” saw the Doctor confronted with the Master’s boldest, most insane plan yet. Having taken command of the Cybermen, the Master uses their planet of Mondas as a gigantic mobile conversion factory, powering it by chaining a living energy source called a Qurunx to the planet’s core. It turns out that he needs this incredible amount of power to enact his final blow: transferring his own mind into the Doctor’s body.

Forcing the Doctor to regenerate into him, the Master takes over our hero’s form… for a bit. Within the recesses of her consciousness, the Doctor is able to hold onto her current persona, thanks to encouraging visions from her past bodies that come in the form of those surprise cameos mentioned above.

Outside the Time Lord’s mindscape, meanwhile, her united friends— with a little help from an A.I. of the Doctor she had activated earlier — are able to reverse the process and get her back. The vengeful Master, however, decides that if he can’t be the Doctor than neither can she and blasts Thirteen with a bolt of the imprisoned Qurunx’s energy.

Knowing what’s coming, the Doctor and Yaz (Mandip Gill) say their goodbyes, with the former wishing to go into their next life alone. After witnessing a sunset for the finale time, the Doctor gives into the regenerative process, but is shocked by what happens next.

After the volcanic energy of her regeneration dissipates, the Doctor is amazed to find they have regenerated back into an old body. Specifically, that of their tenth self. That’s right, David Tennant is the Doctor! Er, again. So what’s happening with Ncuti Gatwa? Thankfully the thrilling teaser for next year’s 60th anniversary celebrations promises that he’s on his way, too.

Why is the Doctor wearing an old face? Is this the doing of Neil Patrick Harris’ super-powerful villain? We’ll get the answers to all these questions and more when Doctor Who eventually returns to our screens in 2023.