In an emotional and eventful episode of Chicago Fire season 12, Brett (played by Kara Killmer) and Casey (played by Jesse Spencer) finally tie the knot in what is described as one of the best weddings Firehouse 51 has ever seen. The ceremony took place at a fish shop and offered a happy ending amidst the usual drama of the show.

However, the wedding also marked Brett's final episode, as Killmer's departure from the show was revealed. But fans of the One Chicago universe need not despair, as Killmer recently hinted at a potential return to the franchise, despite not being part of Chicago Fire season 12.

In an interview with The Hollywood Reporter, Killmer expressed optimism about reprising her role as Brett in the future. She mentioned that the door is wide open for her to return and that she would gladly come back to Firehouse 51 if Sylvie Brett's presence is needed to straighten things out. Her fondness for the show and the importance of the firehouse to her character were apparent in her words.

Interestingly, Killmer's sentiments echo those of Jesse Spencer when he first left the show. Although no longer a main character, Spencer made regular appearances at Firehouse 51 for various reasons. This example shows that there is precedent for departed characters to make comebacks in the One Chicago universe.

Brett and Casey's wedding was pivotal for their story arc, as it allowed for Brett's departure and gave the couple a happy ending. Their relationship faced challenges due to the difficulties of long-distance commitment, and with Casey not leaving Portland, their marriage would not have been sustainable. But the wedding served as a positive way to write out Brett's character and provide closure for fans.

While the possibility of Brett and Casey returning to the Chicago Fire series is not urgent at the moment, there is potential for future storylines that could bring them back to Firehouse 51 for a fun reunion. The writers have proven their ability to craft engaging narratives, and fans can hope for new developments that might entice the characters to return to Chicago.

Chicago Fire season 12 continues to air new episodes every Wednesday at 9 pm ET on NBC. As part of Dick Wolfe's Chicago franchise, the show delves into the lives and careers of public service employees in Chicago, specifically focusing on the firefighters and paramedics of Firehouse 51. The ensemble cast includes Jesse Spencer, Taylor Kinney, Monica Raymund, and Eamonn Walker, among others.