When the Doctor Who Christmas Special premieres on BBC America Christmas Day, fans will see the debut of the Doctor’s (Matt Smith) new companion, Clara, played by Jenna-Louise Coleman, 26. She replaces Amy Pond (Karen Gillan) and Rory (Arthur Darvill).

Coleman appeared in the premiere episode of the previous season, Asylum of the Daleks, in which she plays — what else? — a Dalek. She received positive reviews for her portrayal, with one reviewer even calling her “the star of the episode.”

However, introducing her as the Doctor’s new companion has opened up a lot of questions, none of which will be revealed in the Christmas episode. "We’re going to have what has been referred to as a 'soft mystery,' Coleman told Entertainment Weekly. "For me, filming, I’ve been totally oblivious to Oswin and the 'Asylum of the Daleks.' I really have had to erase it from my memory. Yeah, Christmas is its own episode.”

Coleman has an extensive background in television. From 2005-2009, she was a cast member on the popular English soap opera Emmerdale. She can also be seen in Julian Fellowes’ four-part miniseries Titanic.

The audition process for Dr. Who was an exceptionally creative process. “Well, I had my first audition with Andy Pryor, the casting director," Coleman recalls. "Then they brought me back to read with Matt before Christmas and then I had another session with Matt after Christmas. So it was three all together — but it was lovely, actually. [Eventually] I think there were six people there — producers, casting directors, and everybody — and they actually left the room and left me and Matt to it. I’ve never had that in an audition before. They let us play about and made the scene our own and then they all came in to watch.”