Digital Spy has been lucky enough to get a sneak peek at the first episode, and we're dying to talk to someone about it. We don't want to give anything away, but we've picked out ten teasers to give you some little hints about what's coming up...
1. Everyone's rushing to get ready for the big Mary and Matthew wedding! But will they actually make it down the aisle? A big argument could put a spanner in the works...
2. One of the members of staff goes on strike.
3. You'd think the preparations for a wedding would be a happy time, so what's making the Earl of Grantham sob?
4. Edith's got her eye on a man, and she's being pretty persistent about it, too.
5. Could Thomas and O'Brien start scheming against each other? It certainly looks like their friendship is in trouble... and all because of a new (and "very tall") footman.
6. Downton Abbey is getting saucy! Let's just say that Matthew is looking forward to the honeymoon. It's even making Cora blush...
7. Branson's not feeling too comfortable about being an Upstairs kinda guy now, and the arrival of Sybil's former suitor doesn't help matters (in a more dramatic way than you might expect).
8. Cora's mother Martha - the magnificent Shirley MacLaine - arrives for the wedding and, as you might have heard, she's not best friends with Violet. But what does she find out about the Dowager Countess that surprises her?
9. Bates and Anna fans? They're still separated by Bates's pesky murder conviction, but don't worry - they have their sweet moments.
10. A scene involving a door and closed eyes will make even the hardest of hearts melt inside.
Downton Abbey returns on Sunday (September 16) at 9pm on ITV1.