'Doctor Who' Christmas special update: 'Twice Upon a Time' promises emotional scene between the original and 12th Doctors

The promotional poster of "Doctor Who" Christmas specialFacebook/DoctorWho

BBC recently dropped the new teaser of the coming "Doctor Who" Christmas special titled "Twice Upon a Time" last Friday, Nov. 17, on "Children in Need." It showed the reunion of the original and twelfth doctor played respectively by David Bradley and Peter Capaldi, which surely made fans emotional.

This will be the last time that fans will see Capaldi as the Time Lord before he passes his crown to a new female doctor, Jodie Whittaker. The upcoming season 11, too, will be the first time that the original BBC science-fiction television program will be starred by a female protagonist.

In the "Doctor Who" Christmas special trailer, the first Doctor will be surprised when he first meets the 12th Doctor. Here, he will be seen wondering if someone manages to steal his iconic time-traveling machine.

The original time traveler seems to forget that he is the one who pinched the vehicle even before the show started. When Capaldi's character comes to the scene, he explains he is his regeneration TARDIS.

It has been known that Capaldi will be leaving the show after "Doctor Who" Christmas special. Thus, this will be the time he will be regenerating to become the first female doctor. In fact, this has been hinted by the 12th Doctor's glowing hand.

With that, the coming of "Twice Upon a Time" episode is expected to be a big one. Aside from the appearance of Bradley along with Mark Gatiss as The Captain, this will be the last glimpse of Capaldi as the Doctor since he started in 2013.

And with Capaldi and Bradley's reunion in "Doctor Who" Christmas special, fans are really excited. In fact, the Twitter world has been filled with a lot of tweets when BBC dropped the trailer of "Twice Upon a Time."

"I just fan had a meltdown watching the first doctor return," one fan tweeted. Also, with reference to the first World War, it teased a coming of a very emotional scene. This is mainly because of Bradley's return that brings a lot of flashbacks.

"Doctor Who" Christmas special, titled "Twice Upon a Time," will be released on Monday, Dec. 25 on BBC.