Josh Radnor Josh Radnor

[SPOILER ALERT: The following story contains spoilers about Monday's Season 8 finale of How I Met Your Mother. Read at your own risk.]

How I Met Your Mother told us to "get ready for the mother of all secrets" on Monday's Season 8 finale and it was legendary. That's right: We finally met The Mother! So who is she?

The future Mrs. Mosby, or "The Girl with the Yellow Umbrella" as she is credited, is played by Tony-nominated Once actress Cristin Milioti.

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We still don't know how Ted meets her (except on the train platform, obviously), but now we know the circumstances leading up to that wedding day. It begins with Ted (

Josh Radnor) showing Lily (Alyson Hannigan) his renovated house while Marshall (Jason Segel) brings baby Marvin to Minnesota to see his family before they move to Rome. But Ted's not planning on moving in to the house any time soon — he's actually put it up for sale to move to Chicago, aka "a Cleveland-y New York," the day after Barney (Neil Patrick Harris) and Robin's (Cobie Smulders) wedding because he still has feelings for Robin. (Sigh.) He tells Lily about last week's futile locket search attempt/their handholding in the rain.Lily reveals she knows where the locket is. In 2008, a drunk Robin, lamenting Ted's upcoming wedding to Stella, dug it up to take it with to her to Japan. But Lily had put it in a racecar pencil box, which is in Ted's apartment. "This is going to be the best wedding gift ever," he says. "Ted, be careful," Lily warns.

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Cut to Friday morning. It's 56 hours before the wedding, and everyone's making their way to Farhampton, Long Island, for the nuptials. Barney and Robin had just attempted to break up an obnoxious couple (Casey Wilson and Keegan-Michael Key) at dinner, and Marshall's coming back from Minnesota after learning that there's a judgeship opening for him in New York that he has yet to tell Lily about. Lily and Ted are driving out there, and he plans to take the train back to head to Chicago. And who's buying a train ticket there with her bass guitar and yellow umbrella? The Mother.

The best part of the reveal? They went with an unknown. (Milioti has also guest-starred on 30 Rock as "sexy baby" writer Abby Flynn.) Viewers can't have any preconceived notions of what she might "be" like based on the actress playing her, like they would with, say, Jennifer Morrison or Sarah Chalke (granted Stella would've been The Mother had the show been canceled all those years ago.) Plus, Ted has never met her before, so why should we "know" her? It's hard to imagine anyone would have too much of a problem with the reveal; it was necessary. There'd be hell if they didn't do this. Fans have been waiting and begging impatiently for years to meet her and while there are still puzzle pieces to fit in (the biggest, of course, being her and Ted meeting), this is the optimal way to tease and excite fans to tune in (or come back, in some cases) for the final season."It was a pretty big umbrella to fill, casting the title role in a series that's been on the air for eight years," co-creator and executive producer Carter Bays said in a statement. "And yet Cristin Milioti is, against all odds, exactly what we were looking for. She made us laugh on 30 Rock, she made us swoon in Once, and her ukulele skills are no joke. We're thrilled to welcome her to the How I Met Your Mother family, and look forward to getting to know her — and the character she plays — much better in the coming final season."Bays adds that Season 9 will "tell the epic story of the longest wedding weekend ever," giving more weight to speculation that the whole season will play out in real time. He and co-creator and executive producer Craig Thomas have said that Season 9 will "take some risks with time."What do you think? Are you glad we finally met The Mother? What do you think will happen in Season 9? Check out the clip of the reveal below.
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