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? 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.”

Read more: They're back... David Tennant and Catherine Tate return to Doctor Who
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. Jacqueline King will be reprising her role as Donna’s mother Sylvia, and Karl Collins as Donna’s long suffering husband, Shaun. Plus, Ruth Madeley joins the cast as Shirley Anne Bingham.

What are the Doctor Who 60th Anniversary Specials episode titles?

Moments before the Eurovision Song Contest Grand Final came live from Liverpool, viewers were transported out of this world as Doctor Who launched an explosive new trailer which gave viewers an exciting glimpse of what to expect later this year when the TARDIS lands in time to celebrate its 60th anniversary, and it exclusively revealed the titles of the three special episodes.

Special One: The Star Beast
Special Two: Wild Blue Yonder
Special Three: The Giggle

Russell T Davies, Showrunner says: “The titles are just the beginning of the Doctor’s biggest adventure yet. Autumn is coming, with three hours of danger, Donna and disaster about to be unleashed!”

Watch a teaser trailer for Doctor Who's 60th Anniversary specials below

Watch the video for a taster of what's to come for Doctor Who in 2023 with three anniversary specials below

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'll be a new way to watch Doctor Who globally from 2023

Disney+ is to become new global home for upcoming seasons of Doctor Who outside the UK & Ireland, while the BBC continues as Doctor Who's exclusive home in the UK.

New episodes will premiere on the BBC and Disney+ beginning in late 2023 for fans all over the world.