'Doctor Who' Christmas Special 2013: Steven Moffat admits Matt Smith's regeneration felt like 'very wrong thing to do' in 'Time of the Doctor'

We are less than a week away from the Doctor Who Christmas special, "The Time of the Doctor," which is also the final episode of Matt Smith's run as the eleventh Doctor on the hit BBC series. As is the case with any Doctor regenerations, fans are torn between the sadness of saying goodbye to a beloved actor and excited to welcome the new star (Peter Capaldi). Fans aren't the only one's torn up though. Head writer Steven Moffat recently admitted how writing off Smith felt "very wrong."

"Regeneration scenes are the toughest but most exciting part of Doctor Who - you don't really know the show until you've written one. Previously, I'd only written Matt's end of David's regeneration - this is the first time I've actually killed off a Doctor," the showrunner said.

Moffat added: "It feels like a very wrong thing to do to your childhood, not to mention one of your friends!"

Though he's sad to say goodbye to a friend, Moffat also teased the upcoming eighth season and his excitement over Capaldi's episodes.

"Peter's only just done his first read-through, and now the real work on his Doctor has begun," he explained. "This isn't the time for talking - it's the time for working hard. See you next year!"

What are your feelings of the upcoming departure of Smith and the introduction of Capaldi? Are you excited for the Christmas special or, like most Whovians, are you torn between emotions?

Check out the trailer for "The Time of the Doctor" right here!