Josh Radnor, Thomas Lennon

[SPOILER ALERT: The following story reveals major plot points from the How I Met Your Mother Season 8 premiere. Read at your own risk.]

The end is nigh.

That's what How I Met Your Mother co-creator/co-executive producer Craig Thomas hopes fans get out of the Season 8 premiere's much-anticipated "gasp" moment: The titular mother — bass guitar and yellow umbrella in hand — standing 15 feet away from Ted (Josh Radnor) on the platform of a train station after Barney and Robin's future wedding.

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"We wanted the season premiere to feel momentous because this could be the beginning of the last chapter," Thomas tells TVGuide.com. "There are negotiations happening, but I don't know how that's gonna go and I don't know when I'll know if there'll be a Season 9. Carter [Bays] and I are really writing the season as if it's the last season and this is how we would start it."

The season premiere also found both Barney (Neil Patrick Harris) and Robin (Cobie Smulders) getting cold feet before their nuptials; Quinn (Becki Newton) learning that Barney and Robin had dated, Robin's new beau Nick (Michael Trucco); Victoria's jilted fiancé Klaus (Thomas Lennon) explaining to Ted in the German way he can how to figure who The One is; and new parents Marshall (Jason Segel) and Lily (Alyson Hannigan) totally sleep-deprived.

So what else can we expect in this possible final season? How long has the train plan been in the works? Is that really where Ted and his wife will meet? Get the scoop below.

Was that "gasp" moment exactly how you envisioned it?
Craig Thomas:
Definitely. It's just one of those moments that gives us a chill here, and we hope it gives the audience a chill. It's the finish line of our series. There's something just mind-blowing about that — seeing Ted just be 15 feet away from the love of his life. I hope the people dig it as much as we do here. ... Ultimately, we had to make the decision, like, "Well, there could be a Season 9. Should we hold off?" And then we just decided to kick it off the way we would if it were the last. I'm really glad we did.

Is this actually where they're going to meet? Or is it another close call?
Thomas:
The platform is where they're going to meet. The days of close calls are over. We are in Season 8. We don't know if it's the end or not, but we wanted to show the audience that this is a big deal. We are really thisclose to getting there. Everything that happens in Season 8 will have significance and will be leading us toward that moment. We will see some of the future that happens after that moment. I don't want to say exactly where the series will end and how far we'll get past it, but it's exciting.

When did you decide they would meet at the train station?
Thomas:
We've known they would meet at the train station for a long time. Really, since early in the series we've known it would be this. It's been a slow process of zooming in on her from, like, a shot in space to a train station on the tip of Long Island. We teased a few years ago that Ted was gonna meet her on Barney's wedding day. We magnified it a bit. ... Our Emmy Award-winning set designer Steve Olsen did an amazing job on that train station set. It's 120-feet long and we had to build it on a new soundstage. It really took our breath away. We've been picturing this train station in our heads for so many years and that moment in the rain. Before we started shooting, Carter and I walked over and took a little moment to look at it and go, "Oh my God, we're here."

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Mrs. Mosby has some funky footwear.
Thomas:
The shoes mean she's a little hip, a little quirky. We wanted to throw a little personality into those shoes rather than have them look forgettable or bland. And she has a bass guitar. We know that she may be coming from having played some music. Ted said earlier in the series that he's always wanted to marry a lady who played bass. He's seeing his dream woman walk up on the steps to the train platform in the rain.

Why didn't she just go under the awning to stay dry? She just had to use the yellow umbrella?
Thomas:
We couldn't get them too close! [Laughs] She's over there looking for the train. Maybe she heard the train. We're gonna pick up and show the rest of that moment. I don't want to say exactly when we're gonna catch up to it and see all of that, but we look forward to filling in all the blanks and that could be sooner than later.

Obviously that would happen this season if it's the last, but if there's a Season 9, will we still go back to it this year?
Thomas:
I can't really explain what our plan is gonna be. We have a crazy plan to extend the show. I know, we always have crazy plans, but this is our craziest. If How I Met Your Mother is renewed for Season 9, it will be via a very crazy plan, writing- and storytelling-wise. ... We have a plan where we get to write Season 8 like it's the last and we get to write it like it's the last season until way into the season. I don't want to want to say at which point Plan A and Plan B diverge and break off, but we can write it like it's the last for a while before we really need to know. The cool thing is, it doesn't feel like we have to tread water at all. I don't think the fans will feel like, "Oh, they're just biding their time." Truly, everything is heading toward a conclusion and a finish line that people will feel the sense of urgency.

Ted's not looking too great on that bench. Will we at least flash to Barney and Robin's wedding to see what led to that even if we won't get back to the train station this year?
Thomas:
We'll get to everything eventually. How vague is that? [Laughs] We'll see the story of how we get to Barney and Robin's wedding day and we'll see everything that leads Ted to be sitting there, looking a little disheveled and the worse for wear. Barney and Robin's wedding day is one of the biggest and craziest in the history of this group. Ted has been through an emotional roller coaster that day. He's having a very pensive moment, sitting there in the rain, going over the craziness of the day.

Can you specify when Barney and Robin will get engaged?
Thomas:
It's gonna be a process. I think we have a way to get Barney and Robin back together that is really fun and really appropriate. They get married, so someone's gotta propose to someone. We have the plan and we know what we're gonna do and we hope people will say, "Of course! That's the only way Barney and Robin could have gotten back together." But first they have to break up with Quinn and Nick, obviously.

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That's October — your breakup month.
Thomas:
There is some serious relationship turbulence and some relationship carnage that happens from Episode 2 through Episode 6. It becomes a little murder mystery. The opening of Episode 2 is a three-way split-screen and it's like "One of these three couples will break up." It's the prenup episode between Barney and Quinn. It's hilarious, but one couple does bite the dust in it. Even though we know all the endings — Ted doesn't marry Victoria (Ashley Williams), Barney doesn't marry Quinn, and Robin doesn't end up with Nick — it's just kind of cool to see three very different types of breakups. All three send these three characters into a huge chapter in their lives — Barney and Robin getting together and Ted sitting on that train station platform. We get to play the breakups for fun and milk comedy out of them, but there' s something destiny-tinged about all three.

How much more of Michael Trucco's abs will we see?
Thomas:
[Laughs] You should just tune in and see for yourself! There's a definite physical connection between Robin and Nick. Michael and Cobie are friends and they're hilarious together. We learn some fun stuff about Nick and who he is. He's this TV chef. A few very, very funny issues come up between them, and as we know, they will break up. I do want to say that these breakups aren't occurring for Robin and Barney because of each other. They're happening for different reasons and neither of them is thinking about getting back with the other yet. They range from comedy to real poignancy and sadness.

You said Ted will have a final fling after Victoria before he meets the mom, which a lot of fans weren't too excited about.
Thomas:
I would be upset with us too! [Laughs] But it is just a fling. We're not asking the audience to fall head over heels with his dates, so Ted's romantic escapades between Victoria and the mother will be for comedy and to spin him toward that ending. We do have Abby Elliott. She's a crazy chick who comes into the group's lives and complicates things. But Victoria is the last significant love interest for him.

Is Chris Elliott going to be in the same episodes?
Thomas:
[Laughs] Chris comes around as grandpa Mickey in the third episode. Abby's not in that. Lily and Marshall have to deal with the presence of Lily's deadbeat dad. We think it's a true observation that once you have a kid, you have to redefine your relationship with your own parents. The door is open for Mickey to come back later in the season. I don't want to say if we'll have a Chris and Abby Elliott family reunion on the show, but it'd be cool if we did.

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Has it been hard incorporating Marshall and Lily into a group story line with Marvin now?
Thomas:
Not really. I think we've done a good job with their stories. Episode 4 is basically "Who wants to be a godparent?" I think all new parents go through this: What if something happens to me? Who would this kid go to? That's a very loaded question. You're talking about each other's families and friends. There's some storytelling flair in that episode. We hope the audience will enjoy going down the first year of parenthood with Marshall and Lily. They're one of the best couples on TV. I love them. Jason and Alyson have such amazing chemistry. We were all just at Cobie's wedding and just seeing them hanging out, it's like, "You're just like Marshall and Lily!"

What comes after breakup month?
Thomas:
We've sectioned everything, and [in] Episodes 7 through 12, everyone but Marshall and Lily will be single. And then things will get interesting.

Did you enjoy the glimpse of the "mother"? How would you like this season's breakups to go down?

How I Met Your Mother airs Mondays at 8/7c on CBS.