Clara's spot in the TARDIS won't be empty for long.

'Doctor Who' Season 9: Gallifrey Stands! Twelve To Head Home In The Finale

Doctor Who will say goodbye to Twelve's (Peter Capaldi) companion as season 9 comes to a close, but a new traveler will link up with the Time Lord as season 10 opens. There are numerous theories as to which one-off characters could return to fill the role, but it's looking more and more like Twelve's next companion will be someone we have never seen.

Showrunner Steven Moffat touched on the issue while addressing the chance that Osgood may take on the role.

'Doctor Who' Season 9: Mark Gatiss Has A Long List Of Female Doctors, What's The Hold Up?

"She's a great character and we love her, but whether you really get a relaunch out of bringing someone on board the TARDIS who's already been there, I don't know," Moffat teased, according to Doctor Who TV. "It did work very well with Catherine Tate [as Donna], but that's not the direction we're currently going in."

For his part, Capaldi would like his new costar to have a personality and backstory akin to that of Rose.

"It's one of the things I loved about Billie Piper. That was a very new thing in Doctor Who - to have somebody who lived on an estate, and had a much earthier sound to their voice," Capaldi explained.

Who do you think would make a good addition to the Doctor Who family? Sound off in the comments below!

Doctor Who airs Saturdays on the BBC and BBC America. Click the video below to see a preview for the series' next episode, "Face the Raven."

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