Season three of Downton Abbey finally gets its U.S. premiere on this Sunday, and there are plenty of can't-miss twists and turns in store. How do we know? We've seen it! And now we're sharing a bit of the classy-soap goodness with you. Here, five things to know about the latest episode of Masterpiece Classic's ridiculously addictive period drama.
1. Matthew and Mary's romance is front-and-center. What better way to usher in the spring of 1920 than with an aristocratic wedding? As the premiere opens, long-suffering soul mates Matthew (Dan Stevens) and Mary (Michelle Dockery) are in a church, surrounded by fam and friends, running through a rehearsal for their ceremony. Will they actually get hitched? And will Sybil (Jessica Brown Findlay), who ran off with former family chauffeur Branson (Allen Leech) and is now pregnant with his child, be allowed to attend? Our lips are sealed, but we will say there's one particularly sweet scene between the engaged couple that takes place with a door—yes, a door—between them. Just try not to melt when Matthew says, "Can I kiss you? Because I need to. Very much." And we need you to!
2. Shirley MacLaine is a mayjah drama mama. The Oscar winner-who guest stars as the filthy-rich American mother of Lady Grantham (Elizabeth McGovern) arrives 40-plus minutes into the two-hour episode rocking so much of the color red (scarlet lips! coat! shiny new car!) you'd think she was helping to promote Taylor Swift 's most recent album. In fact, she's brilliantly conveying the character's fiery personality, even before uttering a single incendiary line. Her first words to granddaughter Mary? "Now you tell me all of your wedding plans—and ask me what I can do to improve them." Ahhhh, snap!
3. Bates and Anna are still cursed. Wrongly convicted of murdering his first wife Vera, Bates (Brendan Coyle) continues to rot away in prison as the season begins, a fate his loyal second wife, Anna (Joanne Froggett), refuses to accept. Besides tirelessly attending to every one of Lady Mary's high-maintenance whims, Anna is working overtime to keep her hubby's spirits up and find evidence to set him free. She better hurry: Bates has a shady new cellmate. The kind who likes to utter lines like "I will cut you."
4. O'Brien and Thomas are no longer BFF's. Downton's downstairs villains have long been bonded by their scheming ways and, while they're still cooking up trouble in season three, it's often at each other's expense. The impetus for the change in their cold, black hearts? The arrival of O'Brien's (Siobhan Finneran) nephew, an Army vet and former hotel waiter, who scores a new job as a Downton footman—and threatens to rise up the ranks much faster and easier than a jealous Thomas (Rob James-Collier) did.
5. Shirley MacLaine serenades Dame Maggie Smith. While the legendary actresses spend most of their scenes hurling insults (albeit classy) at each other, there's one brilliant sing-along in which the American heiress manages to render the Dowager Countess speechless. It's likely to never happen again so savor every. hilarious. moment.
Hungry for even more Downton scoop? Watch our exclusive interviews with the cast below!