Go behind the scenes of Kara Killmer’s final “Chicago Fire” episode: ‘This is happily ever after’

Jesse Spencer, Kara Killmer, and more of the cast take you inside the making of Brett and Casey’s wedding.

Sylvie Brett is getting her happy ending.

EW has an exclusive look at this week’s Chicago Fire episode, which will serve as star Kara Killmer’s last. Killmer has played Sylvie Brett on the long-running drama since season 3. But, at least her farewell looks to be a celebration, because not only is it her final episode, but it’s also Casey (Jesse Spencer) and Brett’s wedding!

“Shooting the Brettsey wedding episode has been bittersweet — more sweet than bitter,” Killmer says in the behind-the-scenes video, which you can watch above. Spencer, who left the show in season 10 and has been back a couple of times, adds, “It’s been a long time coming and I think they deserve each other.”

Once married — in a fish store, no less — Sylvie will follow Casey back to Oregon, where he’s lived since he made the tough choice to leave Firehouse 51. But before they go, they’re getting one heck of a party. As Miranda Rae Mayo, who plays Stella, puts it, the episode is “our entire Chicago Fire family gathering to celebrate two people who belong together.”

For Killmer, the farewell is a fitting one. “What I like about where things end is that we are finishing her journey on the show marrying the most eligible, most beloved character in all of One Chicago,” she says.

Her onscreen husband chimes in to say, “It doesn’t often happen, but I feel like this is happily ever after, don’t you think? It kind of does feel like that.”

Chicago Fire airs Wednesdays at 9 p.m. ET/PT on NBC.