Doctor Who: See Peter Capaldi's Time Lord regenerate as Jodie Whittaker

It’s the moment Doctor Who fans have been waiting to see since Jodie Whittaker was announced as the 13th Doctor in July, and it’s finally here. The official Doctor Who Facebook page has posted a video of the scene from the show’s special Christmas episode where Peter Capaldi lets go of being the Time Lord and regenerates into Whittaker.

“The time has come,” the post reads. “Let the regeneration begin…”

“As we discovered at the climax of the last season, the Doctor is about to regenerate, but doesn’t want to,” says Mark Gatiss, who appears in the episode, told EW. “Not because he doesn’t want to change his face but [he thinks] maybe this is time to finish it. And then unexpectedly, out of the snow, arrives his very first incarnation, now played by the great David Bradley…. It’s essentially a kind of chamber piece of David, and Peter, and Pearl [Mackie], and me, and this strange mysterious threat. But really it’s about the wonderful interplay between the two Doctors. Both Doctors are about to regenerate, one of them for the first time, one for the 13th, or whatever it is now. It’s a very charming, funny, and rather moving script.”

The episode, titled “Twice Upon a Time,” was written by showrunner Steven Moffat, who is himself departing the series after eight years. Chris Chibnall (Broadchurch) will take the leads going forward.

“I’m beyond excited to begin this epic journey — with Chris and with every Whovian on this planet. It’s more than an honor to play the Doctor,” Whittaker said in a statement at the time of her casting announcement. “It means remembering everyone I used to be while stepping forward to embrace everything the Doctor stands for: hope. I can’t wait.”

The Doctor Who special Christmas episode premieres on BBC America on Dec. 25 at 9 p.m. ET.