Doctor Who fans have more than a few things to celebrate for its 60th anniversary. Though Jodie Whittaker has departed the series as the Thirteenth Doctor, her regeneration revealed that her successor in the role was none other than David Tennant, who will be returning to the show as the fourteenth doctor for three specials in 2023.

Doctor Who has featured thirteen Doctors during its run. The character's species has the ability to regenerate into a new form. The latest, Whittaker, regenerated in "The Power of the Doctor," and for the first time during the show's run, an actor has returned as the Doctor for a full-time run. Tennant and Catherine Tate, who portrays Donna Noble, had previously been announced to return for Doctor Who's 60th anniversary, and fans got a glimpse of Tennant's return in "The Power of the Doctor."

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In a clip posted to the Doctor Who Twitter account, fans were teased with a small taste of Tennant's new adventures as the Doctor. The clip features brief glimpses at Tennant, now both the 10th and 14th Doctor, who states, "I don't know who I am anymore." Other brief clips, including a shot of Donna Noble and two cars being flung against one another, are also shown. It had previously been teased that Jodie Whittaker's regeneration scene would be different from those of previous Doctors, but the specifics were not revealed.

As it turns out, Whittaker's Doctor Who regenerated outside of the TARDIS, a first for the series. Watching a view of the sunset, the Thirteenth Doctor began to regenerate, only to find himself back in a familiar form. Recalling his old teeth, he begins to realize that he's the Tenth Doctor once more, capping everything off with a "What? What? WHAT?!" before the special ends.

Fans will have to wait a few months before Tennant's return is explained. The Doctor usually does not turn back once he's changed forms, but the Tenth Doctor incarnation proved to be particularly reluctant to go when it came time for him to regenerate. With the news that Russell T. Davies returning to Doctor Who, it's the perfect time to revisit some of the Tenth Doctor's stories. Noble's reintroduction is particularly exciting because her character was left on a fairly tragic note when she was last seen 15 years ago. Tennant was last on the show 10 years ago for the 50th-anniversary special, where he guest starred with Matt Smith in the title role.

Once Tennant's next run is over, Sex Education's Ncuti Gatwa has been cast as the next Doctor Who. He will debut as the Doctor during 2023's holiday celebrations, probably sometime around Christmas. Doctor Who's Christmas specials are well-known, so it's sure to be a good time.

Doctor Who returns to the BBC in 2023.

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Source: BBC Doctor Who/Twitter