'Downton Abbey' Season 4 Spoilers: Paul Giamatti Cast as Mary and Edith's Uncle, New Suitors for Mary

"Downton Abbey" will soon be welcoming another visitor from across the pond. Hollywood Life reports that Paul Giamatti will be joining the cast in season four as another American family member who will be visiting the estate.

The Oscar-nominated actor will be playing Cora's (Elizabeth McGovern's) brother, Harold Levinson, making him Mary (Michelle Dockery) and Edith's (Laura Carmichael) uncle. Gareth Naeme, executive producer for the show, described Giamatti's character as "free-spirited."

Shirley MacLaine will also reprise her role as Martha Levinson, Cora's candid, sharp-tongued mother. MacLaine was featured in an episode in the third season as Mrs. Levinson, who abhors old British traditions and loves to extol the modern virtues of America. She is the American version of the Dowager Countess Violet Crawley (Dame Maggie Smith). She may seem like the polar opposite of the Dowager, but she is just as acerbic and set in her ways as the British matriarch.

The producer's descriptions of Giamatti's character give the impression that Harold takes after his mother, Martha, and is the opposite of Cora. Gareth also hinted that Martha and Harold will "upset the Grantham's apple cart" on the season four finale. Although that is a cryptic description, we know that it definitely means more riveting drama.

Hollywood Life  shared the scoop about what the rest of the blue-blooded family will face in season four. As for the rest of the characters, it is clear that Mary will be "miserable again," according to Michelle Dockery, following her husband Matthew's (Dan Stevens) tragic death in a car accident in the finale of season three. Anna (Joanne Froggatt) and the newly-freed Bates (Brendan Coyle) will not be happy for long-- the producers promise that there is plenty of drama still in store for the couple.

The recently widowed Mary will also have two new suitors, played by Julian Ovenden and Tom Cullen. The suitors are not only vying for her affection, but for her title, and the immense wealth that comes with it.

Gary Carr will join the cast as jazz musician Jack Ross, who will be the show's first black character. Jack will also be connected in some way to young troublemaker Rose (Lily James).

"Downton Abbey" will return to America on Jan. 5 on PBS.