Doctor Who Season 8
The "Doctor Who" Season 8 premiere airs on Aug. 23. BBC

Peter Capaldi and Jenna Coleman have been on a whirlwind tour of the globe to celebrate "Doctor Who" Season 8. While not riding in a TARDIS, the cast traveled to four cities and traveled more than 18,000 miles before landing in New York City on Thursday. Capaldi, Coleman and "Doctor Who" showrunner Steven Moffat discussed "Doctor Who" Season 8 as well as what to expect from the new Doctor and his companion, Clara.

Capaldi and Coleman arrived from Sydney late Wednesday night, although they looked far from jet-lagged. Speaking about the "Doctor Who" Season 8 premiere and its main villain, Moffat said he wanted episode 1, "Deep Breath," to be a simpler story that served to introduce Capaldi's new Doctor. "I wanted a 'simple' menace for the first episode. I didn't want it to be wildly complicated, as it were, because obviously the grandstanding center of it is the new Doctor and his new relationship with his companion," said Moffat.

'Doctor Who' Season 8
Peter Capaldi and Jenna Coleman will star in "Doctor Who" Season 8. IBTimes

"So you really want the villains to be lurching around and offing people now and then with a simple backstory, but I also quite like the idea, and I think I stole this joke from 'Columbo,' but the Doctor's forgotten his previous adventure," said Moffat on the Doctor's difficulty remembering his past after regeneration.

Moffat remained coy about any plans for recognizing Capaldi's past role in "Doctor Who," as Caecilius in "The Fires of Pompeii," but said if there were any nods to his previous role they would be subtle.

In terms of the regeneration, and the discussion surrounding the trend of younger Doctors, Moffat did not focus on that while writing "Deep Breath," as part of the allure of "Doctor Who" involves these 50-year-old traditions, such as the joke that the TARDIS is bigger on the inside or a new actor playing the Doctor after regeneration.

For Coleman, she was excited about the new Doctor as he was a different person who kept his guard up around her. "I wanted to know more because he wasn't telling me everything," said Coleman. "Not so much a charm offensive but just an offensive," joked Moffat.

'Doctor Who' Season 8
Peter Capaldi and Jenna Coleman. IBTimes

Capaldi's lifelong love affair with "Doctor Who" was another topic of discussion, as the actor does not hide his joy in playing a character he's watched since childhood. Capaldi talked about how he asked David Tennant where the TARDIS was on set during the filming of "The Fires of Pompeii" and said he got "a little bit teary" while touching the police box. Filming as the Doctor, his first conversation with a Dalek brought out his inner fan.

Coleman is in an interesting place as she serves as the audience surrogate, linking the previous to the new Doctor, but she was excited about the challenge, and saw the chance of working with Capaldi and a new Doctor as a way to reevaluate the show and Clara. "Expecting a reply from maybe what the Eleventh Doctor would say and, suddenly, this new Doctor does not respond in the same way. I would suppose that's what's jarring, realizing what are the rules now and how this dynamic works," said Coleman.

Capaldi's new Doctor will be quite different from Matt Smith's, and that's partly the choice of the actor and also part of the allure of the character. "The great thing to me about 'Doctor Who' has been that there is an unknown 'Doctor Who,' the character who presents himself to the people around him but there's always the sense that there's another aspect to him which is untouchable and unreachable," said Capaldi.

Peter Capaldi
Peter Capaldi takes over the role of the Doctor from Matt Smith. IBTimes

At the heart of the show is the Doctor and what he really is and means to the people around him. "The Doctor is quite a complicated character. For a melodramtic hero, he's quite complicated and I think you're wasting your opportunity with regeneration if you don't do a bit of that. Because we know he doesn't just change his face, he changes, things about him are not quite the same, things he reaches for are not there. He has feelings he didn't have before, I think that must be awfully alarming and must make you wonder who you are," said Moffat.

"I think there's an element that runs throughout 'Doctor Who,' and what makes it so much better than everything else in the world, is the Doctor does not know he is a hero. He doesn't really know he's in that show. He knows that some other people think he is, and sometimes he seems like he's a legendary warrior, but he knows, and we know because we are watching him, that he's just a man who cannot drive the time machine properly," said Moffat.

"What I think is interesting is that, with everyone talking about the character when, in fact, in the episodes that are so full of incident and drama and adventure, there's barely any time to talk about the character. We just go on dealing with whatever threat that has to be dealt with and yet, there's something enigmatic and appealing about the charcter that makes us want to talk about it all the time," said Capaldi.

Capaldi's Doctor will be entirely his own, although there will be nods to previous Doctors as well as the rich history of "Doctor Who." The relationship between the current Doctor and Clara will be dissected throughout the season, but there will be plenty of action, laughter and scenes that fans have come to love and expect from "Doctor Who."

The "Doctor Who" Season 8 premiere airs on Aug. 23 at 8 p.m. EDT on BBC America. Fans can check out "Deep Breath" in select theaters on Aug. 25 and BBC has also set up a few midnight screenings.