Chicago Fire season 15 is here and fans still ask what happened to Casey: Jesse Spencer came back four times, then went silent
Casey left Firehouse 51 in 2021 to raise his late friend's sons in Oregon. He came back for two weddings, a visit and a proposal, and hasn't been seen since February 2024.
Chicago Fire season 15 premiered on NBC on Wednesday, October 7, 2026, making it the first firefighter drama to reach 15 seasons. Somewhere in this run the show will also air its 300th episode. Jesse Spencer, who played Matt Casey for the show's first ten seasons, is not in the announced cast, and there has been no word of a guest return.
Why Casey left
Spencer played Casey as the lead from 2012 until season 10. He has said the decision was about longevity. Counting back, he realized he had spent close to two decades on network TV between House and Chicago Fire.
As he put it to reporters at the time, "I think this year is my 18th year of network television."
Spencer told showrunner Derek Haas he wanted to leave, and they agreed to get Casey to 200 episodes first. Haas used the extra episodes to reach back to the pilot. In the first episode of the series, firefighter Andy Darden dies on a call, and Casey ends up looking after his young sons. In season 10, a grown Griffin Darden comes back to Chicago, and Casey ends up moving to Oregon to take care of the Darden boys. He left in the show's 200th episode, which aired on October 20, 2021, while keeping up a long-distance relationship with paramedic Sylvie Brett (Kara Killmer).
The four returns
Casey's exit was built to leave the door open, and the show used it four times:
- Season 10 finale, May 2022 — Casey flies back for Kelly Severide and Stella Kidd's wedding.
- Season 11, episode 18, April 5, 2023 — his first appearance since the finale, months after Brett broke up with him in the season 11 premiere. Spencer said at the time that the storyline had Casey considering whether he could move back to 51.
- Season 11 finale, May 2023 — Casey turns up at Brett's door and proposes. The episode ends before she answers.
- Season 12, episode 6, "Port in the Storm," February 28, 2024 — Brett says yes, the two marry, and Brett leaves Chicago with Casey and their adopted daughter, Julia, for a new life in Portland. It was also Killmer's final episode.
After the wedding, both characters were written out together, which made a casual Casey drop-in much harder to justify. He did not appear in the rest of season 12, in season 13 or in season 14.
Where Spencer has been
Spencer went back to Australia to star in Last Days of the Space Age, an eight-episode Disney+ dramedy set in 1979 Perth, which launched globally on Disney+ and Hulu on October 2, 2024.
He has never ruled out returning. After his season 11 episode, he told NBC Insider that the arrangement when he left was simple: if a storyline called for Casey and the timing worked, both sides were open to it. That remains the official position, mostly because nobody has said anything new.
Casey was at the center of the show's 100th episode, when he married Gabby Dawson, and its 200th, when he left. That's the whole case fans are making for the 300th.
The 300th episode is coming this season. NBC hasn't announced who's in it.
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