‘Doctor Who’ Finale Shocks With Regeneration — [Spoiler] Is New Doctor After Ncuti Gatwa’s Exit

Meredith Jacobs May 31, 2025, 3:17 pm

Ncuti Gatwa in Doctor Who — James Pardon/BBC Studios/Bad Wolf

[Warning: The below contains MAJOR spoilers for the Doctor Who Season 2 finale “Reality War.”]

Heading into the Doctor Who Season 2 finale, rumors abound about a regeneration. Usually, we know ahead of time when one is coming, even though we don’t know the specifics (Jodie Whittaker‘s Doctor regenerating into David Tennant‘s, and David Tennant’s then bigenerating to introduce Ncuti Gatwa‘s Doctor, for example). But this time, it’s a shock, and not only does the Doctor regenerate into a very familiar face, but he’s helped along the way by another previous iteration.

In the penultimate episode, the Rani (Archie Panjabi and Anita Dobson, following a bigeneration) created the Wish World — where the Doctor and companion Belinda (Varada Sethu) were married, with a daughter, Poppy (from “Space Babies”) — so the Doctor would doubt and, by doing so, rip open the structure of reality. Then, she could see underneath where “the one who is lost,” Omega (the first Time Lord, the creator of the Time Lords, the greatest and most terrifying Time Lord of all), is hidden. The good news is thanks to help from Anita (Steph de Whalley), it doesn’t take long for the Doctor and others to remember the real world; she now works in the Time Hotel and by opening doors to it, reality seeps through. (But is her boss who gave her one day to help and said to say hello the Meep’s boss?)

Omega does return in the Season 2 finale, and all the time he spent in the underverse has turned him into a monstrous creature, one who wants to consume Time Lords, not create a whole new Gallifrey, like the Rani wants. After he eats the Rani, Mrs. Flood quickly makes her escape. Ruby’s (Millie Gibson) job, meanwhile, is to get to Conrad (Jonah Hauer-King) and the baby, the god of wishes, and take apart this world. (She uses a little something fans will recognize called Project Indigo, just like Freema Agyeman‘s Martha did back in “The Stolen Earth” during Russell T Davies‘ first run as showrunner.) In doing so, however, chances are Poppy would no longer exist, so they’re put into a Zero Room, which exists outside time and space, and should protect them. It all seems to work, and everything seems to be back as it should, only Poppy soon disappears as the Doctor and Belinda are discussing their upcoming adventures, with, then without her. Only Ruby remembers her.

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It takes her a bit of convincing, but Ruby soon gets the Doctor on board with saving Poppy’s life, just like he’d saved everyone else’s at some point. With time shifted by one degree, the only thing strong enough to change reality is the Doctor himself. “I like this face,” he laments once in the TARDIS. He was the best. “Male,” Jodie Whittaker’s Doctor quickly corrects him. Yes, the Thirteenth Doctor shows up — love! — because cause and effect is getting a little out of order, she explains. He’s surprised it’s not the other guy who’s always turning up, he admits. She was popped out of her timeline because of the time schism on the way, caused by him. He’s going to be punching a ton of his regeneration energy into the vortex to jolt it by one degree. A life for a life. But if he ruptures the time vortex, it can damage the whole of creation, she warns. She’s not going to stop him. She hugs him, then remarks that his face is absolutely beautiful. But if he gets this wrong, it could be the last, he says, with no chance of bigeneration either. (Spoilers, Thirteen.)

“We never change,” she says. “All these faces, and we never really change.” She advises him, “Don’t go with fear, go with that lovely smile.” He wishes they had longer. “We always wish that,” she says. As she heads off to her old life, he tells her he loves her, and she says she should tell that to Yaz. She doesn’t, he says, but she knows. And with a goodbye, she’s gone.

James Pardon/BBC Studios/Bad Wolf

The Doctor then does exactly as he planned, and it works, only, Poppy is Belinda’s daughter, and his companion had, in this new reality, been telling him all along that she had to get home to her. The Doctor spends a bit of time with Belinda and Poppy before leaving, having put off his regeneration by a bit, “I can’t have children, but if I could, I wish that she was exactly like you,” he even tells Poppy. (The Doctor and Rani reveal earlier that Time Lords are infertile.)

The Doctor then heads into space to regenerate. “I don’t want to do this alone,” he says, then walks to the doors, opens them, and realizes he’s never alone, not with Joy (Nicola Coughlan‘s character turned into a star in the Christmas special) shining brightly. “That is the exactly the word,” he realizes. “This has been an absolute joy.” And with that, he regenerates into… Billie Piper?! “Oh, hello,” she says with a smile. (Piper previously played the Ninth Doctor’s companion, Rose Tyler. Read all about her here.) Watch it below.