In the trailer, the TARDIS can be seen before the camera cuts to a key buzzing with electric energy.
The number 13 is then splashed across a mobile phone screen, number 10 Downing Street, the White Cliffs of Dover and The Statue of Liberty.
Capaldi recently revealed his regeneration sequence will be "more complicated than recent ones."
Of leaving the show, the star told The Radio Times in June: "I can't go into the details. I know what happens, but I don't know how it happens. Certainly it's not straightforward. It's more complicated than recent ones.
"That's one of the appeals of being in the show - it has death at the heart of it. He's the only hero on TV who dies again and again."
There are suggestions that directors of the show are looking to take it in a different direction with a woman taking on the role on the back of its 52 years of success.
A source told The Sunday People: "[BBC] bosses love Phoebe. They thought she did an amazing job with Fleabag and is certainly one of the rising stars in TV and film."
"They see her as the perfect fit as a Time Lord and the first female Doctor Who."
Waller-Bridge has remained mum on the subject.
"I am not allowed to say anything about that, one way or the other," she said in a recent interview.
It comes as Kris Marshall revealed he is leaving his long-running series Death In Paradise after four years on the BBC show, so that he can spend more time with his family.
