“I realized I’ve been doing TV for a long time,” Spencer told reporters on a Zoom call to announce his departure. “I added it up and this year is my 18th year because I went straight from House to Chicago Fire. We were coming up to the 200th episode, and so I called [showrunner Derek [Haas] and I broke the news that I’m leaving the show. He agreed that we should at least get Casey to the 200th episode. It was a difficult decision because I’ve loved this show from the start, but there’s other things that I would like to do in the future and family that I need to take care of.” In the episode, Casey made the decision to move to Portland to serve as legal guardian to Ben and Griffin Darden, whose father Andy—Casey’s best friend—was killed in a fire in the Chicago Fire premiere episode. The boys’ mother Heather is in jail, so unless Casey stepped in, they would be put into foster care and most likely separated. “I was very happy that Jesse gave us five more episodes rather than just saying at the end of a season, which happens sometimes, ‘I’m out,’” Haas said. “So, that let us bring back a storyline from season one, 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.” Of course, there was the problem of the new relationship with Sylvie Brett (Kara Kilmer), which after three years of will they-won’t they, finally was they will. And now Casey is moving to Portland. He does ask Sylvie to come with him, but she has just launched the paramedicine program, so is no position to leave Chicago. “Derek used it well in the storyline that Casey is leaving and going to Oregon for the right reasons, so it all felt really organic,” Spencer added. “It was difficult because I really like Kara. We’ve established a really nice relationship. I loved working with her. We got on so well and you know there is the chance that I will come back, too, so we’re toying with the will Casey come back? Derek and I talked about that and that that’s a possibility.” As a result, Haas plans to keep their relationship alive long distance, even though Spencer isn’t filming any inserts to include in future episodes, but we may hear his voice. “We’re in a day and age where because of FaceTime, easy airline tickets, and phone calls, it’s possible,” Haas said. With the possibility of Casey’s return, one major event where he could be sorely missed if he didn’t appear would be the wedding of Kelly Severide (Taylor Kinney) and Stella Kidd (Miranda Rae Mayo) at which Casey is supposed to be the best man. “How could I not?” Spencer told Parade.com, so it could be something to look forward to. While Haas added, “I’m hoping. Here’s the thing, I never try to predict what is going to happen production wise. We’re in the camp of whenever Jesse wants to come and do an episode with us, we will move mountains to make that happen. So, we’ve been talking. We’ve got some ideas and I would say you’ve hit the nail on the head as to what some of those moments might be.” As for who will take over command of Truck 81 in Casey’s absence, it remains to be seen. Haas isn’t giving away too much because it involves a future storyline. The one thing that is for certain is that Herrmann (David Eigenberg) will remain engine lieutenant. “We’re doing a major storyline over who’s going to be the next commanding officer of Truck 81, so I don’t want to spoil anything but that becomes a storyline through the winter break because obviously there is some shifting chairs within the firehouse,” Haas said. But Spencer’s departure also opened up the door – and the need – for Boden to return to Firehouse 51 when his assistant figured out that it was now the center of the area that the chief oversees. “If Jesse is leaving, it felt like we needed somebody there to keep it from being so untethered,” Haas said. “As we were mapping out all of these moves, one of them was having Boden come back.” The last scene that Spencer filmed was on the burn stage for the church file in episode 200, Casey’s final fire – for now at least – in Firehouse 51. “It was hard to film that,” he recalled. “It was a strange feeling on set, but a happy feeling. It was bittersweet. Everyone started hitting these pipes on the ground and chanting. It became this semi-pseudo tribal sendoff for me. It was awesome. It was something else. When we finished, they wheeled out a cake and had speeches. It has been a great crew, a great cast. I couldn’t have asked for anything more.” Chicago Fire airs Wednesday nights at 9 p.m. ET/PT on NBC. Next, See the First Photos! The Heat Is On When Chicago Fire Returns for Season 10!