With 10 action-packed seasons behind her, we bid farewell to Chicago Fire fan favorite Sylvie Brett (Kara Killmer).  But make no mistake: She didn’t leave Chicago Fire without a fitting 51 send-off.

Since Season 3 of the NBC nail-biter, Brett has been stealing hearts as 51’s compassionate paramedic. Throughout her impressive tenure, Brett fell in love with former CFD firefighter Matthew Casey (Jesse Spencer), prompting a turbulent long-distance relationship.

Thankfully, “Brettsey” has finally decided to ditch the distance. Casey popped the question in Season 11, and Brett said yes. They’re starting a new chapter as husband and wife, and Brett’s moving to Portland for it.

Fans are sad to see Brett leave Chicago, but no one can deny it’s the perfect happily ever after for the cherished characters.

Brett and Casey’s wedding was so beautiful. It was an intimate ceremony where their 51 loved ones gathered to celebrate their union.

Sylvie Brett and Matt Casey’s Chicago Fire wedding went swimmingly

Despite the initial panic over the venue (Brett thought she got a hook-up for Chicago Shedd’s Aquarium, but it wasn’t the case — instead, it was in a commercial fish store), Brett and Casey’s wedding couldn’t have been more perfect. Brett’s maid of honor, Violet (Hanako Greensmith), orchestrated a miraculous transformation of the space to set the scene for a heartwarming ceremony, officiated by none other than Chief Boden (Eamonn Walker).

Despite their long-distance relationship, it was like Casey never left as the couple swapped their tear-jerking vows.

“Sylvie Brett, getting here to this place was the toughest battle of my life,” Casey began. “But it was worth every moment because we’re here now. You are my port in the storm. The most generous, caring person I’ve ever known. And sometimes the most stubborn…”

“So not true,” Brett countered.

“You would say that,” Casey retorted, earning a chuckle. “We were apart for too long. Now, I promise that you’ll never be alone. I will always be by your side. And that this, the two of us together, is a fire that will never go out.”

After a solid firefighter pun (Casey with the dad jokes), it was Brett’s turn. Brett revealed the first moment she knew she wanted to spend the rest of her life with Casey — after going to the Shedd Aquarium with her young half-sister and Casey and seeing how good he was with kids. The hunch was only amplified after Casey left Chicago to become a legal guardian to the two Darden boys left behind after Andy Darden’s passing.

“It only made me love you more, even though I was trying so hard to let you go,” Brett confessed tearfully. “And I couldn’t. It’s just like you said, we were meant to be. And we were meant to be a family.”

Brett turned to the room, adding, “And I have one more thing I want to say: All I wanted was for this wedding to be simple, intimate, and perfect. And it’s all of those things.”

Not a dry eye was left in the room after Casey and Brett’s vulnerable ceremony. Brett and Casey shared their first kiss as a married couple as Firehouse 51 applauded with glee. Brettsey is officially forever!

After a lively reception at Molly’s, Brett and Casey’s loved ones gave them another round of applause as they jumped in the car and onto their next horizon as husband and wife.

Kara Killmer bids farewell to Chicago Fire with NBC Insider

NBC Insider chatted with Killmer about Brett and Casey’s wedding and Brett’s legacy at Firehouse 51.

Killmer says the opportunity to act alongside Casey for her final episode was one of the best parts of the send-off.

“We picked up right where we left off, so it was really sweet getting to have him back for this episode,” Killmer said. “It was like he never left.”

Brett and Casey’s wedding is easily one of the most romantic Brettsey moments, and for Killmer, the secret to the scene’s success was in the vows.

“I think one of the things that’s refreshing about this episode is in their vows, they are finally getting to say to each other face to face what everyone has understood, but it’s kinda been left unsaid, you know?” Killmer explained. “You don’t frequently get to hear them talk about how much they love each other, and so that was something that was very satisfying about filming the wedding is that you finally get to hear them say to each other what everyone has been seeing and feeling and thinking for, you know, the last, like, five years.”

She continued, “I think their relationship has really matured, both of them, in a beautiful way that none of the other relationships they’ve been in have been able to do. It is just so satisfying to get to see them finally make that commitment to each other and everyone will get to picture in their minds and fantasize about what their future together is gonna be. I know I do.”

Boden reminded Brett and Casey that regardless of where they go, they can always return home to Firehouse 51. As for the possibility of a future guest appearance from Brett on Chicago Fire, Killmer would be elated at the opportunity to reunite with the One Chicago family.

“Oh, absolutely,” Killmer said. “The door is wide open. Any time they wanna call, I will be there. It is a fantastic show, great people. I will come back any time they want.”

Watch Chicago Fire on Wednesdays at 9/8c on NBC and the next day on Peacock.