'Downton Abbey' season four

Big change is in the air in season four of "Downton Abbey." Though most of the cast is back, several beloved faces will be missing -- most notably Jessica Brown Findlay's Lady Sybil and Dan Stevens' Matthew Crawley, whose characters died in season three. Siobhan Finneran, who plays O'Brien, left the show between seasons.

Lady Mary (played by Michelle Dockery) may be a new mom and widow since husband Matthew died in the season finale, but come the new year, she's going to have "more than one love interest," the actress said.

The ladies of Downton Abbey -- Mary, Cora (Elizabeth McGovern) and Edith (Laura Carmichael) -- will be down one Crawley sister when the show returns. Lady Sybil died last season.

Branson (Allen Leech) lost his wife Sybil last year after she gave birth to their little girl, also named Sybil. But the family finally embraced him and made him the estate's agent. Lord Grantham was very resistant to change last season, so Branson may have his work cut out for him -- along with being a newly widowed dad.

The men downstairs -- footman Alfred (Matt Milne), footman Jimmy (Ed Speleers), Mr. Carson (Jim Carter) and underbutler Thomas (Rob James-Collier) -- will all be back in season four. But former trouble maker O'Brien won't be around to stir the pot this time.

Butler Mr. Carson will continue to be a stickler for proper etiquette and behavior at Downton Abbey, but don't expect him and good pal Mrs. Hughes to get all lovey-dovey. "No. No. We still have a very nice working relationship," Phyllis Logan, who plays the head housekeeper, said at the TV critics press tour this summer.

Sophie McShera's Daisy was a pill last season, being a brat of epic proportions toward new girl Ivy. The actress teased at TCA that her character will still not be the most pleasant of people.

Scheming underbutler Thomas is losing his nemesis, lady's maid O'Brien, this season. With her gone, "Thomas will get a little more control back this time and start to run things his way downstairs," executive producer Gareth Neame told TODAY.com.

In-laws Mary (with baby George) and Tom are single parents this upcoming season. A clip shown at TCA hinted that the relationship between the two will grow, but strike any thoughts of a potential romance from your heads. "Romantically, I don't think it's going anywhere," Dockery said.

Wild child Lady Rose, the Dowager Countess' great niece, is back again. In a clip shown at TCA, Rose tries to get maid Anna (Joanne Froggatt) to be her chaperone for an event in the village, that may not be exactly appropriate for someone of the young lady's station.

One of the new men in Lady Mary's life this season will be Charles Blake (Julian Ovenden). According to TV Guide, he'll make his first appearance in episode 4. "He's modern-thinking but does not share the family's sentimentality about the past," Neame told the magazine. He also said that Mary and Charles aren't going to like each other when they first meet.

Get ready for some jazz this season. The drama will introduce Jack Ross (Gary Carr) in the third episode, according to TV Guide. "Ross is very positive, ambitious and charming," Neame told the magazine about the singer from Chicago.

Lord Gillingham (Tom Cullen), an old family friend, will make his debut in the second episode of the season. "She hasn't seen him since she was tiny," Dockery said of the new character at TCA.