Chicago Fire’s Kara Killmer Talks About Her Exit, ‘Difficult’ Journey to Long-Awaited #Brettsey Wedding

Wedding bells are ringing in the Windy City: The day that Sylvie Brett and Matt Casey ‘shippers have been waiting for on Chicago Fire is almost here.

The couple will finally get married during this Wednesday’s episode (NBC, 9/8c), but the happy occasion is somewhat bittersweet. The hour also doubles as star Kara Killmer‘s final one as her character, Brett, and Casey prepare to start their new life together in Portland. It’s been a rocky road, getting to this point in the pair’s relationship, complete with a failed try at long-distance dating, then seeing other people, and finally, the epiphany that they just can’t live without each other.

For Killmer, saying goodbye to Brett now, when the paramedic has come into her own on the job and gotten her dream man, made sense. “This is a natural conclusion for the arc of Sylvie’s character,” the actress tells TVLine in the following Q&A.

With happily ever after in sight, “I’m very satisfied with where things end up for Sylvie,” Killmer adds.

Below, Killmer talks about saying goodbye to the show, previews her favorite part of Casey and Brett’s intimate wedding, and mulls what the future may hold for the couple. (Hint: It involves more diapers.)

TVLINE | When did you know it was time to leave the show? And what went into your decision?

I think this is a natural conclusion for the arc of Sylvie’s character. I sort of love that she started her journey [when] she was dumped at the altar by her high school boyfriend and runs off to Chicago to start over again, and I love that she ends up across the aisle from the love of her life and, obviously, the most eligible bachelor in all of Chicago and Portland. It’s just so satisfying to get to see her have everything that she always wanted and to see the kind of woman she’s become, the sort of paramedic she’s become. She’s really stepped into her own, and so, this is a natural conclusion for her.

TVLINE | For you, personally, did you feel like you had done as much as you could with Sylvie and that it was time for maybe something different and something new?

I mean, I’m certainly excited to see what other projects are out there, for sure. It’s definitely been so humbling and aspirational to be playing a first responder for this long. I couldn’t be happier to have been in this story space, getting to work with real firefighters and paramedics this long. If you’re going to spend 10 years somewhere, you want to spend it in a place like our show, for sure. But yeah, I’m very excited to see what else is out there on the horizon. There’s a lot of interesting content that’s being created right now. And I’m very satisfied with where things end up for Sylvie on Fire.

TVLINE | Sylvie’s farewell episode is also the long-awaited Casey and Brett wedding. How important was it for you that Brett’s story end with her and Casey together and married?

I think the audience has been on the journey with Sylvie, they’ve been through all of her different relationships. She dated Cruz, she was with Antonio Dawson, she almost got married to the chaplain, Kyle Sheffield. And then she started this three-year journey of being with Casey, and then had a couple of flings on the side with Grainger and Dylan. I just think that throughout all of it, she always wanted to be in a loving, committed relationship, and she always really wanted to partner with somebody.

I think [in] all of her previous relationships, somebody always wanted too big of a compromise from her, and she’s definitely the kind of girl who would try to do the mental gymnastics. She would try to bend over backwards to make things work until they wouldn’t. I think what’s different about the relationship with Matt Casey is that he never wanted her to compromise. He always called her to a more mature, more honest, more dependable version of herself that even she hadn’t realized yet, and I think that’s what’s special about their relationship.

So I love that the person she ends up with is the person who brings out the best in her. And I think that’s true vice versa. In all of the years that Jesse [Spencer] and I got to play the relationship with these characters, my sole goal was to always try and make him break and laugh in our scenes together, because Casey is such a hard-ass, and he’s so serious, and he has the weight of the world on his shoulders. I always wanted the dynamic of our relationship to just be that Brett brings a little sunshine into his corner. And so, I was constantly trying to make him laugh.

TVLINE | Even after Jesse left the show, the writers really tried their best to keep the Brett and Casey romance alive, but it kind of was up and down, back and forth, they’re together, they’re not together, they’re dating other people but they’re still in love. Was that difficult for you, being so invested in the character and the relationship, and to not have that kind of stability?

For sure. I was just as attached to their relationship as the fans were, and so I was glad that they didn’t break up. But I also felt the same sort of like, “What are we going to do?” because he’s not here. I think, honestly, what the writers were attempting is exactly what everybody who’s ever had a long-distance relationship can relate to, which is it’s hard. You sort of reach like an expiration. After about three weeks, you start to go, “Do we still love each other? Do you still like me? Are we still in this together?” It’s really difficult to maintain.

Obviously, they got on that shaky ground, and she tried to let him go and she dates Dylan, and she becomes aware of the same thing that the audience is aware of, which is just, “You had him. Matt Casey is it for you. There’s no one else out there.” So when he comes back at the end of Season 11 and does what Matt Casey does by going behind the scenes and helping her out and making sure that she and Julia end up together, it’s just so indicative of their relationship. By the time he’s proposing, there’s just no question that they have to be together.

TVLINE | Now they are finally making that commitment. What is your favorite part of Casey and Brett’s wedding?

I love that Boden is officiating. I love all of the people that come together to be in their small, intimate wedding. I, selfishly, even though Tony totally has the biggest blunder of all, I love that you get to see a little bit more of their relationship. Even though he screws it up, it still all comes together. It’s such a staple of our show to have one character with a huge problem that the rest of 51 then have to go in and team together to find a solution that’s even greater than what anyone could have imagined. So it’s a perfect kind of quintessential 51 problem solution.

But I must say, I think the most fun I had was at the reception, and that was in Molly’s. I stood next to a three-tiered cake for about four hours, and I gotta tell you, I put a hurtin’ on it. When nobody was looking, I was doing some quality control. I was making sure that it was up to par, and it was delicious. So that dress was a little tight by the end of my last day.

TVLINE | You and Brett have both formed such strong bonds in Chicago. Which was the most difficult goodbye or scene to film? Which one made you most emotional?

I have such a special relationship with both Hanako [Greensmith, who plays Violet] and Miranda [Rae Mayo, who plays Stella]. I definitely had the hardest time saying goodbye to Hanako. On one of our last incident days, it was my last day to drive the ambulance, and I kind of just took a moment and sat in there by myself and just sort of said like, “Thank you.” This just sounds stupid, but I said thank you to the ambo for taking care of me and sheltering me in the cold for 10 years, and also, just look after Hanako. I’ve had seven partners on this show, and she is just so special. I’ve never laughed so much in my life. She’s so funny, and she’s so smart, and she’s just been such a wonderful friend. So I, mostly, will miss getting to tell more story with her and Miranda, for sure.

TVLINE | Is the door open to see Brett and Casey again? Would you be up for revisiting them?

I hope so! If the door’s open for them, the door’s open for me! I would be more than happy to pop in anytime. You know, 51 has a unique way of getting itself into trouble, and we love to see familiar faces, and so I’m happy to come back anytime.

TVLINE | What do you hope the future holds for Brett and Casey? More babies maybe?

I hope so. I think so. Casey, ever since Season 1, all he wanted was to be a father. So whether they’re adopting children and kind of creating a patchwork of a family for themselves or — Yeah, I hope they get on it and have a couple of babies themselves. That would be great. That’s how I picture their future for the next couple of years, for sure.