'Chicago Fire' Shocker: Star Explains 'Difficult Decision' to Leave in Season 10

The actor and showrunner Derek Haas discuss Wednesday's monumental 200th episode and the story behind the surprising departure.

Spoiler alert! Do not proceed if you have not watched Wednesday's milestone 200th episode of Chicago Fire.

Casey out.

Chicago Fire celebrated reaching the milestone 200th episode on Wednesday, but it was a bittersweet one as the firehouse said goodbye to one of the leaders at 51, Captain Matthew Casey, after he decided to relocate to Portland, Oregon, to lead the firehouse there in fighting forest fires. The episode, which featured the return of a key storyline with the Darden boys from season 1, marked Chicago Fire star Jesse Spencer's final episode as a series regular after more than nine seasons.

During a press conference-style Zoom call with reporters earlier in the week, Spencer explained the "difficult" decision to exit the firefighter drama in season 10 and during a monumental landmark moment for the OneChicago franchise. The 42-year-old actor noted that the grueling back-to-back 18-year TV run on House and Chicago Fire was part of the reasoning behind his departure, a decision he made at the end of season 9. 

"We were coming up to the 200th episode. I called [showrunner] Derek [Haas] on making a personal decision and broke him the news that I thought it was time to leave the show. And he agreed that we should at least get Casey to 200 episodes," Spencer said. "It was a difficult decision because I've loved the show from the start. But there's other things that I would like to do in the future. There's some family that I need to take care of. And 18 years is a long time, that's a long stretch. I was marking off these milestones and looking to the future... Derek didn't want me to leave, but we both agreed that if it was time for me, then it was time. It was a difficult decision, and I hate to leave the show because I do love this show. But when the time comes, the time comes."

"I feel like all of us feel anything past the first 13 episodes was a bonus. You just don't know when you sign up and move to a different part of the country and stay on, that you're going to be on as long as you were. I feel like we've been in borrowed time for a long time," Haas, who also participated in the conference call, acknowledged. "I, of course, want to talk Jesse into staying and coming back, and doing all of the things as long as we could. But I was very happy that he gave us five more episodes than just saying at the end of a season, which happens sometimes too: 'I'm out.' That let us bring back a storyline from season 1, which I know Jesse was excited about when we pitched it to him, to bring back the Darden boys and really tie in the pilot to Jesse's leaving."

Lori Allen/NBC

But this won't be the last time viewers will see, or rather hear, Spencer. Haas revealed during the call that Casey's presence will still be felt even after Wednesday's episode: "We are going to hear his voice after the 200th."

Haas choked up when asked about the genesis of the emotional goodbye scenes between Casey and Boden (Eamonn Walker), Severide (Taylor Kinney) and the other members of 51 to close out Spencer's time on Chicago Fire. 

"Every now and then, you write scenes that you want the cast and crew to hear what's going through your own head. I don't want to talk too much because I might get emotional, but you get to put into a way better speaker than yourself, Eamonn Walker, things that you wanted to say to them. So that was a really difficult scene to write," he said of the closing minutes of the episode when Boden told Casey he would be "dearly missed." "You feel it intensely. Sometimes you picture what it's going to be and then it's better than what you thought it was going to be. Look, Jesse meant so much to me. I wanted to end the episode with that. In fact, I never do a preamble in a script but in this one, because it was the 200th episode, I had a little preamble in the script about what the crew and the cast and everybody means to me because it really is special. I don't know that it'll ever happen again like this."

"When we were trying to figure out how to write me out by the 200th, we were spitballing a little bit and then the idea of bringing Griffin and Ben [Darden] came back up and it felt like full circle because we didn't want to kill Casey," Spencer added. "But how do we get him out? He's using this new relationship [with Brett] and things, I think, were going relatively well.... It was a really, really, really nice full circle for Griffin to show back up and Ben's in trouble and the mom's in jail and he can't really bring them to Chicago as he first thought that he could. To go back to the house where we filmed the pilot... was awesome. We had that time for Casey to go over how his best friend died and have to explain it to his son, I was just trying to hold it together. The guilt and the longing and then the desire to pull together and help the kid, which is what he always wanted, and the hope for the future, were the things that really stood out. So I had to sit on this stuff and it was hard. It was really hard, but great. It felt so organic for me and a perfect full circle and a really reasonable way for Casey to organically leave the show."

Of course, Spencer leaving Chicago Fire comes at a cost in regard to the further exploration of Casey and Bretty's romantic relationship. After seasons of gradual progress in the romance department, the two finally coupled up. And while the couple will remain in a long-distance relationship after Casey leaves for the West Coast, splitting the two up on opposite sides of the country so soon after they got together weighed heavily on Haas and Spencer.

"We'd been establishing this relationship for three years and we finally just got there. Derek used it well in the storyline that Casey's leaving and going to Oregon for the right reasons. It all felt really organic. It was difficult because I really like Kara [Killmer, who plays Brett]. We've established a really, really nice relationship... We got on so well and there is the chance that I will come back, too," Spencer shared, adding that it's a very real "possibility" he'll pop back into 51 in the near future, especially with Severide and Kidd's wedding looming. "It was written really well into the episode because they're trying to make this relationship work. They know that he's leaving. So they're saying nothing's going to change."

"We're going to keep it alive," Haas reassured. "We're in a day and age where, because of FaceTime and easy airline tickets and phone calls... that's just part of the world. Nothing changed. This is a three-year commitment that Casey's making, but hopefully we'll see him before those three years are done." He added that in the aftermath of Casey's exit, Brett will be part of "some interesting storylines" that will take much of her focus.

Adrian S. Burrows Sr./NBC

"We're going to see, obviously, aftereffects with Brett. It's going to be hard on Brett going into a long-distance relationship, and not knowing what the rules are of a long-distance relationship, and all of that will be a big part of what's going on at the beginning of the season," Haas added later. "We have Severide obviously looking at Casey's quarters going by in the next episode and what that means to him. Then we'll play around with everyone's reactions to that. Obviously, the Truck 81 is the big storyline going forward, who's going to be in command there."

Spencer reflected on what he'll miss most now that he'll no longer be in Casey's shoes day in and day out on the Chicago Fire set. 

"I think all the being on set stuff. You know who I'm going to miss as well, who's been a really big inspiration -- not just the cast, the writers when they come in, the locations that we go to and all the rigmarole that we get up to when we're doing stunts -- is [consulting producer] Steve Chikerotis because he's the guy... What would Casey do is what would Chik do? He's our real-life hero," the actor said. "He's got a big heart, but he's got a strong arm as well. I wanted Casey to live up to who Chik was -- a slightly younger version than Chik -- because he's really been the heart and soul as our fire consultant. He's the guy that we look to, he's the guy that we trust."

"But I've made such good friends on this set. It hasn't really sunk in that I've left really. I feel like I'm just on hiatus for a little bit. It probably won't kick until next year probably," Spencer admitted, sharing that he's still living in Chicago. "But I've made such good friends on the cast and crew that I still get to see people. I just saw Patty Flueger [from Chicago P.D.] down at CVS, just had a chat. We all live in the same neighborhood and so we see each other around. I saw Jason Beghe playing soccer with his son down at the park a few weeks ago. It's still a community and it still feels like a nice brotherhood."

"You know what I'm going to miss?" Spencer said after a beat, before quipping, "I'm going to miss ordering everyone around. I liked yelling at a firefighter when they do something wrong. That was fun."

Chicago Fire airs Wednesdays at 9 p.m. ET/PT on NBC. For more, watch below.

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