On the eve of "Doctor Who's" Series 9 premiere, Jenna Coleman has she's leaving the popular sci-fi drama.

"I have left the TARDIS --  it's happened," she told BBC Radio 1 this morning. ""I've filmed my last scenes."

As previously indicated, Coleman is moving on to star in an ambitious ITV drama about the early years of Queen Victoria's reign, beginning with her ascension of the throne at age 18. "She is a vivid, strong, inspirational and utterly fascinating woman in British history and I can't wait to tell her story," the actress said.

Coleman was revealed in March 2012 at the Doctor's new companion Clara Oswin, succeeding the fan-favorite Karen Gillan (however, she actually made her "Doctor Who" debut not in the Christmas special, as announced, but in the Series 7 premiere, where she played  Oswin Oswald).

The actress, who's starred opposite both Matt Smith and Peter Capaldi, didn't reveal just when Clara will exit the series.

"It's been in the works for a very long time," Coleman said. "Steven [Moffat] and I sat down a year and a half ago and tried to work out the best place to do it and tell a really good story. "We're not going to give any details but it will happen at some point this season. ... We worked out a really good story arc out so hopefully people will love it."

"Doctor Who" returns Saturday on BBC One and BBC America.