Alyson Hannigan, Jason Segel, Neil Patrick Harris and Josh Radnor will wrap up "How I Met Your Mother" this season.

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"How I Met Your Mother" cast previews details of final season

New episodes will focus on Ted's relationship with mother from show's title

The whole season will take place over a single weekend

CNN  — 

Last season’s finale of “How I Met Your Mother” finally answered the lingering question of who exactly is the mother of the TV series’ title.

The show’s main character, Ted Mosby, played by Josh Radnor and voiced in narration by Bob Saget, has spent eight seasons telling his kids the story of how he met their mom, endlessly dragging out the eventual interaction. Finally, creators Carter Bays and Craig Thomas revealed the mother’s identity; she is played by Cristin Milioti.

The CBS show will enter its ninth and final season on September 23, with an hourlong episode, giving one last chance to play out the stories of Ted and his friends before – we hope – seeing him happily settle down.

The creators, episode director and producer Pam Fryman and cast members Radnor, Neil Patrick Harris (Barney Stinson), Cobie Smulders (Robin Scherbatsky), Alyson Hannigan (Lily Aldrin) and Jason Segel (Marshall Eriksen) teased the upcoming 24-episode season recently at the San Diego Comic-Con.

During a panel on the show, the creators unveiled a clip that explains why Ted’s children have been sitting on a couch listening to him tell this never-ending saga.

It ties in with something to come later in the season involving the kids, which Bays said they shot during the second season for whenever the ending arrived.

“We thought we’d be done after eight seasons,” Bays told after the panel, “so season nine is a bonus year and it’s the Wild West. Anything could happen. We’re changing a lot of the rules about how we thought we’d tell the story.”

Thomas added, “I don’t think the story has changed, but how we tell it has changed now that we have 24 extra episodes to see more of it. Knowing what we have left to tell, this little story we’ve been meaning to tell for eight years now, it would have felt really abrupt to end it after eight seasons.”

“How I Met Your Mother” has traditionally used multi-episode narrative arcs and flashbacks to keep the story moving, often jumping in time or extending a season over the course of a year. The final season, however, will take place entirely over one weekend in the fictional town of Farhampton.

“There’s a mass migration to Farhampton, to the Farhampton Inn, for Barney and Robin’s wedding,” Radnor told CNN. “We last left our gang when Lily and Ted were driving out together, Barney and Robin were driving out together and Marshall was planning to come back from Minnesota for the wedding. It’s a road trip. Everyone has various problems along the way, because that’s what happens on television. We pick up literally where we left off.”

Last season left the door open for the resolution of several storylines. Robin, preparing for her wedding to Barney, enlisted Ted’s help finding a locket she’d buried in Central Park and found herself in a romantic moment with him. Lily and Marshall (and their infant son) were about to move to Italy for Lily’s job when Marshall was offered a judgeship in New York but didn’t know how to tell Lily.

“It seems like it’s something Marshall wants to tell her in person,” Segel said. “Which I think is smart. I don’t know how they’ve planned time-wise for the season; they could wrap it up in the finale for all we know. We find out the day before the table read. It’s neat for us to see things unfold.”

Hannigan added, “I don’t like to know too much because I don’t want to have to lie. I’m a terrible liar, so I really don’t know, but he obviously doesn’t want her to find out, and it’s going to be one of those ‘Is she going to find out?’ stressors for Marshall.”

The real draw for the last season is getting to watch the beginning of Ted’s relationship with the mother unfold. Fryman confirmed fans will see Ted meet the character very quickly into the ninth season and said viewers are “going to get to know her.” As the characters gather for the wedding, the on-again, off-again nature of Ted and Robin’s relationship will also be addressed, something at which the season premiere’s title, “The Locket,” may hint.

As for the revelation of Milioti in the role of the mother last season, the creators said keeping that secret was the hardest thing they’ve done on the show.

“We shot it on this other stage,” Bays said. “We built this big train station set you saw in the season finale. We didn’t have any extras. Everyone else you saw walking around there is the ‘How I Met Your Mother’ writers (and crew). It was a family affair. No strangers or outsiders were a part of it. We locked it down. We made everybody (who) was there – not that we don’t trust our cast and crew – sign confidentiality agreements. We were terrified for a month and a half. Every day we were terrified that it would get out, but it didn’t and that was great.”

The cast members seemed emotional about “How I Met Your Mother” coming to an end, but Harris said they are just trying to enjoy filming this season.

“I compartmentalize things, and I’m not a fan of goodbyes so I haven’t really contemplated it,” Harris said. “I don’t want to spend the time we have on the show lamenting its demise because we’re not there yet. We’re still in the beginning of the show. So even though it’s run eight seasons, we still have 20-some odd weeks to do it, and I want to make sure we’re enjoying it as opposed to being wistful about it.”

Smulders, who also appears in the season premiere of the new ABC show “Agents of S.H.I.E.L.D,” said, “It hasn’t started to sink in yet. But we have six more episodes after the holidays, and I feel like that’s going to be a really intense time for everyone.”

Smulders also shared a piece of trivia about the series that surprised even her co-stars.

“Robin was not a Canadian when I signed on for the show,” Smulders said. “She became one because, according to Carter and Craig, we’re exotic. Literally the words they used to me in season one: ‘Well, I just feel like it’s really exotic.’ I never in my life have been called exotic.”

For Radnor, “How I Met Your Mother” has meant being involved in something groundbreaking in terms of storytelling. The extended arcs and serialized narrative structure was not widespread when the show premiered, but it has since become part of the TV landscape.

“We introduced some stuff that is now commonplace in some ways,” Radnor said. “I was actually talking with Carter and Craig last night about how there’s this new fashion of dumping 12 episodes out. Like Netflix is now giving all these episodes, and they can do really serialized arcs. That’s what Carter and Craig excel at. That’s what they always wanted to do. Follow the locket or follow these different threads.

“I feel like in some ways we just did what we did really well, and the public mood caught up to us. When you’re at the top of the mountain and you look back, you say, ‘Wow, we got to do some incredibly strange, amazing moments of television.’ “