Everyone is just catching their breath after the big Doctor Who 50th Anniversary celebrations, but the BBC remind us that there is more to come. On Christmas Day the annual, now-traditional special episode will air and this one will be dramatically more special than the previous years.

“The Time of the Doctor” as it is now titled will see current Doctor Matt Smith saying goodbye to the role he has occupied since the first day of 2010. As the episode closes we will see the eleventh (Twelfth? Thirteenth?) Doctor regenerate yet again and Peter Capaldi will assume the part.

Recent interviews with showrunner Steven Moffat seem to hint that the previously established twelve regeneration limit will come to head as we now know that there was a previously unknown regeneration in the form of John Hurt’s “War Doctor” and it appear that the “diverted regeneration energy” brouhaha from 2008’s “Journey’s End” still decreases the count by one.

However it plays out, we only have a few short weeks until “The Time of the Doctor” and the answers to some long-standing questions. In the meantime, check out the trailer below and look for all the hidden Easter Eggs in the official poster above.

Doctor Who’s 50th Anniversary will truly be celebrated worldwide. BBC America has announced that the special episode, “The Day of the Doctor,” will air simultaneously across the globe in at least 75 countries and spanning six continents.

“Few TV shows can still lay claim to being appointment viewing but Doctor Who takes this to another level,” Tim Davie, CEO of BBC Worldwide, said. “In its 50th Anniversary year we wanted to create a truly international event for Doctor Who fans in as many countries as possible and the simultaneous broadcast and cinema screening of the special across so many countries will make for a fitting birthday tribute to our Time Lord.”

The list of countries airing the special at the same time as the UK include the U.S., Mexico, Brazil, Canada, Colombia and many more. Additional countries are expected to be added over the next month. BBC America is also set to announce soon select 3D screenings of the special episode in U.S. theaters.

It’s the news Whovians everywhere have been waiting for. The Tenth Doctor (David Tennant) and Rose (Billie Piper) will be return to Doctor Who for the 50^th Anniversary. John Hurt is also slated to appear alongside current the Doctor (Matt Smith) and his companion Clara (Jenna-Louise Coleman).

This news comes as a surprise, though a very welcome one, to Doctor Who fans. As we reported only a few days ago, Steven Moffat himself was not confirming any details and just a week ago John Barrowman (Captain Jack Harkness) confirmed he wouldn’t be involved in the anniversary. Tennant was last seen as the much beloved Tenth Doctor in 2010’s The End of Time, which was also the last time we saw Piper’s Rose.

“Doctor Who is the most exhaustingly planned show on earth.” So says the show’s lead writer and executive producer, Steven Moffat, in an interview today. Moffat admits that he encounters few surprises when putting together the show that encompasses all of time and space but there are plenty of surprises for the audience.

The second part of season 7 begins with The Bells of Saint John, which will kick off Jenna-Louise Coleman’s run as the Eleventh Doctor’s (Matt Smith) newest companion. Speaking about Coleman, Moffat said Clara brings a wit and unimpressed quality to the TARDIS and the Time Lord that makes the Doctor work harder to be impressive. “They have enough in common and yet enough sharp contrast,” said Moffat, referring both to the Doctor and Clara as well as Smith and Coleman.

Adding to the uniqueness of Clara is that the Doctor has already met two other versions of his new companion. Regarding whether Clara will ever remember or learn about those other encounters, Moffat jokingly replied, “I would know the answer to that question and certainly won’t give it to you.”