Monica Raymund made her long-awaited return to Chicago Fire in Wednesday's emotional fall finale that saw Cruz (Joe Minoso) honor his late best friend Otis (Yuri Sardarov) and Casey (Jesse Spencer) and Dawson (Raymund) reignite their epic love story in the Dawsey moment to end all Dawsey moments.

The episode, titled "Best Friend Magic," found Dawson back in town for a few days to attend a special gala. The event presented the perfect opportunity for her to reconnect with her ex-husband, Casey, who's struggled in the romance department ever since they divorced. With Casey as Dawson's date, the pair steamed up the dance floor before ending the night together in bed. While they aren't exactly back together, Dawson did leave Casey an open invitation to visit her if he ever found himself in Puerto Rico. Judging by that sly smile on Casey's face when he listened to her voicemail, he's more than likely going to take her up on that offer.

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The hour also delivered a sweet nod to Cruz and Otis' close friendship, with Cruz finally fixing Otis' drone after putting it off for so long. The moment was particularly sentimental for showrunner Derek Haas, whose real-life grief inspired that bittersweet moment. The Chicago Fire boss opened up to TV Guide about the story behind that Crotis nod and how it will help Cruz moving forward. Plus, he weighed in on that epic Dawsey moment and what it means for Brett (Kara Killmer) and Casey, along with teasing what's next for Stella (Miranda Rae Mayo) and Severide (Taylor Kinney).

Monica Raymund and Jesse Spencer, <em>Chicago Fire</em>Monica Raymund and Jesse Spencer, Chicago Fire

How dare you give us this amazing Dawsey moment knowing fully well that she's going to leave right afterward.
Derek Haas:
Yeah, how dare I? Back in June, the writers and I [had our] fingers crossed that we would get Monica to agree to come back. I just thought it would be a great winter finale, checking in on her and what she's doing. They had a connection. You saw six seasons' worth of it, so to me it felt like a natural progression — or regression, if you will.

Why did you give them such an open ending as opposed to permanently closing the book on their relationship?
Haas:
I think real life doesn't have as many closed endings. With the way her life is going and where she's gonna be throughout the world, who knows when they'll cross [paths] next. A lot of times, years and years go by between people who have that kind of connection and [things pick] back up again. That's how it is with her and Casey. What they did have was special and I wanted to honor that. I was never really crazy about the way we ended things, so it was awesome to write.

Is this Monica's only appearance this season or will she be back?
Haas:
This is it for now. I'm not gonna close the door on it this season or next season. She knows I am so persistent with her but she's great and having her back on was really rewarding for me and nostalgic at the same time.

Dawson left Casey an open invitation to visit her right when things are getting pretty weird between Brett and Casey, with these longing stares and acting way too interested in each other's dating lives. What's going on with them?
Haas:
[Dawson's invite] is a pretty big wrench to those looks. I do think we'll continue to explore Brett and Casey's friendship. They're pretty much cut from the same cloth and they do enjoy each other's company and if things head in that direction, I don't think it's unnatural. Although, I think this adds a giant wrinkle to that plan, if there was a plan.

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Speaking of wrenches, we've got Severide facing off against an arsonist for hire who looks ready to blow the whole building up. How worried should we be about Severide?
Haas:
You should be really worried. There's a lot of people in that building. In this guy's mind, had Severide not walked down into that basement, he was gonna light the place on fire and torch any evidence he had and duck out and he didn't care what was upstairs. So you have a guy with nothing to lose and he's looking at a long prison sentence. Very dangerous.

Arsonist aside, things have been going pretty well for Severide at OFI. Is he considering staying there permanently or is he still determined to get back to the firehouse?
Haas:
I think Seager is a part of why it has been more fun and less boring than he thought it would be. She's got such a great energy. We didn't want to introduce a character that was gonna be some rival for Severide who was manipulative like Hope was. This is a woman who's obviously really competent at her job and rose through the ranks at a young age. When we were pitching this section of the season, we just kept referencing The X-Files and what a great relationship Mulder and Scully have. Not the sexual chemistry but more of just the friendship, brother-sister vibe. Where it goes from there, we'll see. But it's definitely more appealing than what he thought it was before he got there.

In the episode, Casey points out that Seager has been giving Severide some looks. Is there something more between them? What's happening there?
Haas:
Severide's only got eyes for Kidd, so whatever else is happening, that's beyond Severide's control. I'll let that play out as the season progresses and you can see where we're going with that. But I don't wanna portray Seager as anything other than really good at her job. Of course, when you have Severide working next to you, you start thinking of deepening your friendship.

Stellaride has been pretty stable over the last season and a half. What's next for them?
Haas:
Severide is pretty much boyfriend of the year and that was important to us. Severide, last year, made this pronouncement to her that he was going to try to live up to what she deserves in a relationship. And we just said, 'You know what? He's gonna do that for Season 8.' We've stuck to it so far for the season. Where that progresses to is gonna make up a big chunk of the emotional real estate of the second half of the season.

Monica Raymund and Jesse Spencer, <em>Chicago Fire</em>Monica Raymund and Jesse Spencer, Chicago Fire


You said there will be a wedding and we've accepted that it's gonna be Cruz and Chloe. But is there potential for another couple to tie the knot?
Haas: Chloe accepted Cruz's proposition so now you know where that one's going. Whether or not there's more than one, I don't know. But I would look forward to a Cruz-Chloe wedding this season.

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Cruz got closure in this episode by fixing Otis' drone. Do you think he's now in a position to really move on with his life?
Haas: We didn't want Otis' death to be something that was just swept under the rug after Episode 1 and everybody just moves on. You've seen it as a central theme, that memorial which Boden says at the end of the first episode, 'If you see someone down here, you walk down here and you bring his memory to life.' And we saw it in Episode 8 with Herrmann and you see it again with Dawson standing at the memorial. From the back, you can't tell [who it is] and Casey walks down there with this growing realization that maybe it's ultimately the love of his life down there and it's just another nod to Otis.

This drone story came out of my real life. I was in college and a really good friend of mine named Tommy died in a car wreck and it caught everybody completely by surprise. It was really terrible and sad and we all grieved. Two years later, I was graduating from graduate school and I found this video camera and just couldn't remember what was on the tapes. I plugged it into my computer and it was a poker game that we all had and the camera was going down with people talking to me because I'm holding the camera and then it swings over and it was my friend Tommy. His face was right there. As I was watching, I just burst into tears [like Cruz does at the end of this episode]. So I've just hung onto that story for a long time and thought, 'OK, this is a way we can do that story with Cruz and Otis.'

I don't think of this too much as closure for Cruz, but it's a reminder that what Cruz and Otis had was special and will always be there. And if anything, he's not spinning out as much as he was in the first half of the season.

What are you excited to explore in the second half of the season?
Haas: I'm very excited about Cruz's wedding. We've been talking a lot about that. We've had a bunch of weddings on this show so you're always trying to do something different that is meaningful to the characters. That wedding will happen earlier in the season [before] the season finale.

Chicago Fire will return with new episodes in 2020.