Doctor Who: Why David Tennant has returned in regeneration, when is show back on TV and where is Ncuti Gatwa

Tennant, who played the 10th incarnation of the Doctor, left the show in 2010 after three series and a number of specials.

He returned to the role for the 50th anniversary but the beloved actor – considered by many to be their favourite to play the character – has been absent from the show ever since.

But in last night's The Power of the Doctor, Jodie Whittaker’s regeneration led to a surprise twist, with Tennant taking her place at the top of Durdle Door.

Here’s why Tennant is back, and what it could mean for the show going forward.

Why is David Tennant back?

Following in tandem with Jodie Whittaker’s departure is that of showrunner Chris Chibnall, with Russell T Davies returning in his place.

Davies was the showrunner at the start of the revival, working with Christopher Ecclestone and later David Tennant.

Upon returning to the show, Davies has confirmed that Tennant will be starring in a special episode next year, tying into the show’s 60th anniversary.

Catherine Tate will also return as fan-favourite Donna Noble, Davies announced – and leaked set photos have showed her and Tennant on screen together.

What happens next

Tennant’s return, in terms of the show, could mean a number of things.

BBC has confirmed Tennant as the 14th Doctor and Ncuti Gatwa as the 15th, meaning this new incarnation will only be temporary.

Given how Jodie Whittaker’s finale played out, fans believe that Tennant’s regeneration is the result of a battle within the Doctor’s ‘mindscape’ with Tennant’s incarnation not yet ready to hang it up.

Fans have also speculated as to whether this version of the Doctor could even be the Valeyard – a dark interpretation of the character from the classic series.

As far as the specials go, fans seem to think the first episode will revolve around the Doctor finding out why he reverted to a previous incarnation and realizing this is temporary, and potentially fixing up how things ended with Donna Noble.

It’s also expected that there will be some form of tribute to the late Bernard Cribbins, who died earlier this year.

Having been pictured in the trailer in a buttoned-down version of Tennant’s outfit, Gatwa is due to also make his debut as the titular character.

When is Doctor Who back on TV

Fans will be left to speculate for quite some time before getting any answers.

Showrunner Russell T Davies has confirmed that the three specials, commemorating the 60th anniversary, will begin broadcasting in November next year.

Further than that, all we know is that the specials are being aired around the ‘festive season’ so specific dates are not known at this time.