It's been announced that one of the biggest movie stars of all time is set to make an appearance on British drama Downton Abbey.

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On Wednesday, The Guardian mentioned that Gravity star George Clooney will be showing up in the Christmas special as an American character who is a guest at a wedding in the country estate.

It turns out that the actor reportedly filmed all of his scenes, but no other specific details were given. However, there is the possibility that he will be acting alongside Hugh Bonneville and Michelle Dockery.

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The site also posted some details that came from The Sun where insiders talked about Clooney becoming a guest star on the series even though it sounded like a rumor.

"All of the plans have been shrouded in secrecy because George was determined for his role not to leak out," a source said.

"All the other cast members and crew were also sworn to secrecy," the source continued. "It's amazing it's taken four months for someone to find out. This is the biggest moment in Downton history and shows it's now the biggest drama in the world."

As for how the rest of the series will go, one detail that's been released is that Anna and Mr. Bates will have some issues to deal with after the sexual assault and possible murder.

"They start Season 5 in a not-so-positive light," Joanne Froggatt (Anna) told Vanity Fair. "Obviously they have a lot to overcome and it won't happen very quickly."

Downton Abbey Season 5 is expected to premiere in the United States in January 2015 on PBS.

Tags: Downtown Abbey television PBS