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On January 6, Shirley MacLaine comes to Downton Abbey when the Oscar-winner joins the cast as Lady Cora's mother, Martha Levinson. And today, the cast stopped by Anderson Live to reveal what it was like working alongside another (props to original H.B.I.C. Dame Maggie Smith) living legend!

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"We didn't know what to expect because this is a Hollywood legend," said Jim Carter, who plays Mr. Carson. "She just rolled up her sleeves and was one of the gang instantly, absolutely instantly. She was one of the gang but with much better quality of gossip."

Cooper also asked about Highclere Castle (which stands in as Downton Abbey) and found out that the owners are still very much living there. "It is lived in by the Carnarvon family," Hugh Bonneville (who plays Lord Grantham) said, adding, "So it's a little bit of life mirroring art, so it's a bit spooky some times."

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Julian Fellowes, who created Downton Abbey, knows the family and Elizabeth McGovern (who plays Lady Cora) says that Julian has "deemed many of the stories from the family."

But one story you couldn't make up involved the Egyptian exhibit Highclere castle was hosting during production of season three -- one that MacLaine, who has been very vocal about her past life experiences, felt was incredibly inaccurate.

Carter recalls, "At Highclere Castle, there is a big Egypt exhibition because Grandfather Carnarvon would discover King Tutankhamun's tomb in Egypt and Shirley went to visit it and thought a lot of it wasn't particularly authentic because she had lived there. She slept with Tutankhamun and she remembered it very well."

Anderson Live airs daily and Downton Abbey premieres January 6 at 9 p.m. on PBS.