Doctor Who's BBC centenary special delivered quite the twist as Jodie Whittaker's Thirteenth Doctor regenerated into none other than David Tennant.

But what does it mean for the Fourteenth Doctor, Donna Noble and new Who star Ncuti Gatwa? To partially quote Gatwa's Doctor, here's everything we know about "what the hell is going on here".

How did Jodie Whittaker regenerate into David Tennant?

"How? What? Why?" Showrunner Russell T Davies has said that fans will have a year to speculate about what's happening before "all hell lets loose" in three special episodes marking Doctor Who's 60th anniversary.

"“If you thought the appearance of David Tennant was a shock, we’ve got plenty more surprises on the way!" he adds.

What's the air date for Doctor Who's special 60th anniversary episodes?

The three special episodes are set to air in November 2023.

What's the plot?

That's a very good question.

Speaking at the time David Tennant and Catherine Tate's return as the Doctor and Donna was announced, showrunner Russell T Davies teased: "Maybe this is a missing story. Or a parallel world. Or a dream, or a trick, or a flashback. The only thing I can confirm is that it’s going to be spectacular, as two of our greatest stars reunite for the battle of a lifetime.”

We also know Heartstopper's Yasmin Finney has joined the cast as Rose, who will somehow be involved. And there's also a mysterious new character played by Neil Patrick Harris.

How can there be another Rose in Doctor Who?

As Russell T Davies says: "You’ll find out in 2023, but it’s an absolute joy to welcome Yasmin to the Doctor Who set. We all fell in love with her in Heartstopper, one of those shows which changes the world - and now Yasmin can change the Whoniverse!”

Who is the Fourteenth Doctor?

David Tennant, previously known as the Tenth Doctor, is now also known as the Fourteenth Doctor. Confused? Don't worry, he seems a little perplexed too.

In a teaser for the upcoming episodes the Fourteenth Doctor can be heard confessing that he doesn't really know himself any more!

When will Ncuti Gatwa's Fifteenth Doctor's first official episode air?

Ncuti Gatwa's first official Doctor Who episode is due to air over the festive period in 2023.

And showrunner Russell T Davies has promised that "the path to Ncuti’s Fifteenth Doctor is laden with mystery, horror, robots, puppets, danger and fun!"

There's a new Doctor Who companion stepping into the TARDIS

Millie Gibson joins the cast of Doctor Who as Ruby Sunday, new companion to Ncuti Gatwa's Fifteenth Doctor.

She'll be making her debut over the festive period in 2023 and she can't wait. "It is a gift of a role, and a dream come true, and I will do everything to try and fill the boots the fellow companions have travelled in before me," she says.

And there's also a mysterious new character played by Neil Patrick Harris.

Doom’s Day will kick off on Doctor Who digital channels later this year followed by products from Doctor Who Magazine, Titan Comics, Penguin Random House, East Side Games, Big Finish and BBC Audio, each telling a section of Doom’s story.Each partner will create their own adventures for Doom’s Day, each focusing on one of the 24 hours Doom has left on the clock. The standalone stories will also have an overarching narrative that will play out before the finale which will release on Doctor Who digital channels.

More details on each individual Doom’s Day storyline will be revealed.

The TARDIS lands in time to celebrate its 60th anniversary, and the trailer exclusively revealed the titles of the three special episodes coming later this year.

Special One: THE STAR BEAST
Special Two: WILD BLUE YONDER
Special Three: THE GIGGLE

The BBC has been blocked from releasing the first Doctor Who story by the son of writer Anthony Coburn following a vicious dispute over the broadcast rights. Directed by Waris Hussein, An Unearthly Child was the show's debut story, introducing William Hartnell's First Doctor as he, granddaughter Susan (Carole Ann Ford), and schoolteachers Ian Chesterton (William Russell) and Barbara Wright (Jacqueline Hill) travel from 1960s London to humanities' earliest days. Broadcast on November 23, 1963, the episode was overshadowed by the coverage of US President John F. Kennedy's assassination but has since been recognized for its pivotal place in pop culture.

While the BBC iPlayer's expanded Doctor Who library will feature nearly every story in time for the 60th anniversary, the BBC has revealed to RadioTimes.com that all four episodes comprising An Unearthly Child will be omitted due to disputes over the show's rights.

It’s a good time to be a Doctor Who fan, especially if you have a Disney+ subscription. The streamer on Wednesday released the official trailer for its upcoming trio of Doctor Who specials, which reunite the Fourteenth Doctor (played by David Tennant) with Donna Temple-Noble (Catherine Tate) “as they come face-to-face with their most terrifying villain yet: the Toymaker” (Neil Patrick Harris).

The first special, “The Star Beast,” will stream on Saturday, Nov. 25, followed by “Wild Blue Yonder” on Saturday, Dec. 2, and “The Giggle” on Saturday, Dec. 9. The specials will premiere globally on Disney+, except in Ireland and the UK, where they will be broadcast on the BBC.

Also returning for the specials are Jacqueline King as Sylvia Noble, Karl Collins as Shaun Temple, and Jemma Redgrave as Kate Lethbridge-Stewart. Newcomers include Yasmin Finney as Rose Temple-Noble, Miriam Margolyes as the voice of the Meep and Ruth Madeley as Shirley Anne Bingham.

Additionally, Disney+ has confirmed that the next season of Doctor Who (starring Sex Education‘s Ncuti Gatwa as the Fifteenth Doctor) will premiere sometime in 2024.

...HBO Max will continue to be the streaming home of Doctor Who (2005), The Sarah Jane Adventures, and Torchwood, until July 27th, 2025.

To understand why this is happening, we’ve consulted with the Time Lord himself (itself?) for a history lesson. Prior to HBO Max, the USA streaming rights for Doctor Who catalog were held by Prime Video. This deal started March 27, 2016 when Series 1-8 joined the Prime Video library. In August 2019, WarnerMedia (now Warner Bros Discovery) announced they had acquired the streaming rights for their upcoming launch of HBO Max. This pact also included the spin-offs, Torchwood, and Sarah Jane Adventures as well as additional BBC series including Luther and The Office. Doctor Who Series 1-11 arrived on HBO Max at launch on May 27, 2020.