Shirley MacLaine Downton AbbeyShirley MacLaine is joining the cast of Downton Abbey, the ITV series that airs in the U.S. on PBS’ Masterpiece Theater and just won the Golden Globe for best miniseries. Our colleagues at TVLine report that MacLaine will play American-born mother of Elizabeth McGovern’s character Lady Grantham. She is set to appear on the third season of the series, which begins production this month. (Season 2 is just wrapping on PBS here.) “My late grandfather directed Shirley MacLaine in Gambit in 1966,” said Downton Abbey executive producer Gareth Neame, “so it is a delight for me that she will be joining us on Downton Abbey.”