'Downton Abbey' has just wrapped up its fifth season and while its cast and crew are busy working on transitioning to season 6, it appears that one lead star is already planning her departure from the show ahead of its return on ITV.

Per Variety's report, 'Downton Abbey' star Maggie Smith is already prepping her exit from the show ahead of the series return on the small screen for its sixth run.

Smith remarkably plays the Dowager Countess of Grantham in the British period drama series, and just when fans are anticipating her appearance and sharp-tongued lines in the upcoming seasons, the 80-year-old television and film actress has already announced that season 6 will be her last.

"They say this is the last one, and I can't see how it could go on," Smith recently told the Sunday Times. "I mean, I certainly can't keep going. To my knowledge, I must be 110 by now. We're into the late 1920s."

However, as opposed to some speculations that she is retiring from the limelight, Smith is actually thinking of engaging into other projects, Express has learned.

"When you're not working it's scary, and when you are working it's scary, because you don't know if you've got the energy to get through the day," she said.

"But the bleakness of not doing it, and missing out on the friendships that you make, is too much to bear," Maggie, who currently appears in "The Second Best Exotic Marigold Hotel," added. 

Smith, who is best known for her acting in the successful 'Harry Potter' franchise as professor Minerva McGonagall, is also set to appear in an upcoming film "The Lady In The Van."

"One isn't safe after doing Downton," Smith quipped. "I've gone through my whole life without any of that. I could go round galleries and things on my own and I just can't do it now."

The mother of two is a notable actress who has bagged numerous awards including two Academy Awards, five BAFTA Awards, three Emmy Awards, three Golden Globes, four Screen Actors Guild Awards and one Tony Award, according to The Telegraph.