'Downton Abbey' Season 3 preview: The cast reveals what's to come, both upstairs and downstairs

Dave Nemetz
The 'Downton Abbey' Season 3 cast -- Carnival Film/Television Limited for Masterpiece

Christmas is right around the corner… but “Downton Abbey” fans have another gift coming their way in just a few weeks. Season 3 of PBS’s sumptuous period drama arrives on our shores on January 6, with more complications for the aristocratic Crawley family and their fleet of servants in 1920s England.

Yahoo! TV attended a special “Downton” screening and Q&A with several cast members in Los Angeles last night, where they handed out “Free Bates” T-shirts -- a sly wink to the show’s incarcerated valet, Mr. Bates. We got a sneak peek at the first 20 minutes of Season 3, which the crowd of rabid fans greeted with wild applause. (Emmy winner Maggie Smith, as “Downton’s” imposing Dowager Countess, got the room laughing with just a look.) We came away with plenty of scoop on what to expect this season; here are five things to look for when the doors to Downton swing open again.

[SPOILER ALERT: The following reveals key plot developments in the upcoming season of “Downton Abbey.” Read on at your own risk.]

A worthy adversary for the Dowager Countess
If you’re a “Downton” fan, you’ve surely heard that Oscar winner Shirley MacLaine is coming aboard this season as Martha Levinson, mother to Robert’s wife Cora (Elizabeth McGovern)… and instant nemesis to Maggie Smith’s Dowager Countess. This epic clash of the titans turned the rest of the “Downton” cast into starstruck groupies. Rob James-Collier, who plays scheming butler Thomas, says he wasn’t even in the scenes between MacLaine and Smith, but he stood by anyway to watch the fireworks. For executive producer Gareth Neame, MacLaine was the perfect choice to stand toe-to-toe with Dame Maggie. “We had to find an actress who could be a formidable opponent for the Dowager,” Neame says. “I think Shirley MacLaine would be at the top of that list, and I’m not sure who would be second.”

No money, mo’ problems for the Earl of Grantham
For the first time on “Downton Abbey,” finances become an issue this season when Robert, the Earl of Grantham (Hugh Bonneville), learns that the family fortune may have been sucked dry by a bad investment. (Bonneville jokes, “I think Robert met a man named Bernie Madoff.”) The prospect of losing Downton is a devastating blow to Robert’s self-worth. As Bonneville explains, “his whole purpose in life is simply to hand over Downton in good order to the next generation.” That’s why Robert’s deep-pocketed mother-in-law Martha gets called in: “There’s hope on the horizon that she will bail us out,” Bonneville hints.

Get a sneak peek at "Downton Abbey" Season 3 right here:

Matthew and Mary: Happily ever after?
Season 2 ended with a happy ending for “Downton’s” primary love story, with Crawley family heir Matthew (Dan Stevens) romantically proposing to Robert’s eldest daughter Lady Mary (Michelle Dockery) on a perfectly snowy night. And this season opens with Matthew and Mary preparing for their lavish society wedding… but don’t expect smooth sailing for the pair. “Of course there’s no guarantee that they actually walk down the aisle,” teases Neame. “The friction and volatility will always continue for that couple.” (We wouldn’t have it any other way.)

“Anna Bates Investigates”
The blue-collar equivalent of the Matthew-Mary relationship is the sweet romance between laconic valet Mr. Bates (Brendan Croyle) and sunny maid Anna (Joanne Froggatt), which turned tragic last season when Bates was wrongly convicted of murdering his nasty ex-wife, Vera. Things are looking up for the couple, though: Bates has been spared the death penalty, and Anna is determined to clear his name, digging around for clues on the outside. Froggatt coyly refers to Anna’s Season 3 detective work as “Anna Bates Investigates.” (We smell a spinoff!) And she says she’s gratified by all the viewer affection for Anna and Mr. Bates: “They’re not the most glamorous part of the show… but they have a real respect for each other, a real loyalty to each other. And there’s nothing that will shake that. There’s something really quite romantic about that.”

Sybil forces Downton to get with the times
Robert’s youngest daughter, Sybil (Jessica Brown-Findlay), threw everyone for a loop in Season 2 by running off to Ireland with Branson, the family chauffeur. Now she returns to Downton with him as her new husband, exposing a growing divide between the old guard and the new generation. Bonneville recognizes which side Lord Grantham stands on: “We now see he’s a bit of a dinosaur… he wants to go back to that era before the war. Matthew and Branson become the voice of modernity, dragging Robert and the rest of the estate into the 1920s.” Well, let’s not get too modern here; we still love those vintage “Downton” costumes, after all.

Haven't seen "Downton Abbey"? Get caught up with this clever five-minute recap:

Be sure to check back with Yahoo! TV before the “Downton Abbey” season premiere for more scoop, including our extended interviews with Joanne Froggatt (Anna) and Rob James-Collier (Thomas).

Season 3 of “Downton Abbey” premieres Sunday, 1/6 (check local listings) on PBS.