The Real Reason Kara Killmer's Sylvie Brett Left Chicago Fire

Contains spoilers for "Chicago Fire" Season 12, Episode 6 — "Port in the Storm"

Kara Killmer joined the "Chicago Fire" cast in 2014, playing Sylvie Brett. A decade later, she's saying goodbye to the character and the One Chicago franchise — but not before getting married to her sweetheart, Matt Casey (Jesse Spencer). Casey and Brett's big wedding is set to take place on the episode titled "Port in the Storm." Before the bash, Kilmer reflected on Brett's journey with TV Insider.

When asked about knowing how it was time to leave the show, the actor responded, "I think this is definitely the natural conclusion for Sylvie's character arc." Longtime fans may remember that Brett's backstory includes previously being engaged to another man and being left at the altar. She and this other man even try to make it work again to no avail. Now, after all this time, Brett's finally getting a happily ever after.

Brett and Casey will be off to Portland, Oregon after the wedding, which is being held in — of all places — a fish store. It's a minor detail, as Killmer believes Brett marrying Casey in any shape or form is all that needs to happen: "It's such a satisfying ending for my character."

Kara Killmer is open to returning as Sylvie Brett ... with a condition

Sylvie Brett and Matt Casey aren't planning on hanging around Chicago much longer after the wedding, starting a new life for their family elsewhere. So "Port in the Storm" will be a farewell for the ages. During the TV Insider interview, Kara Killmer also discussed the last "Chicago Fire" sequence she filmed. "The last scene we shot was the reception at Molly's, so it was truly just one big party," she explained. "I am very happy with the fact that in my last scene, I get to wear a gorgeous dress, and I'm standing next to basically a tower of cake. It doesn't get much better than that."

Brett may be going, but it doesn't necessarily mean she'll be gone for good. After all, Casey left on Season 10 and returned for guest appearances throughout Seasons 11 and 12. Brett could do something similar, perhaps visiting the Windy City to check on her old friends. If Killmer is going to reprise the character, she wants one major change to be in order: "If Sylvie makes an appearance at 51 again, she better be pregnant." Brett already has an adopted daughter, but the actor wants her to start having babies the old-fashioned way.

Goodbyes aren't always necessarily the end. Killmer sounds game to return if the team needs her: "Anytime they want to ask, I will be there, for sure. The door is wide open for me." 

"Port in the Storm" airs on NBC on February 28 and becomes available the following day on Peacock.