'Chicago Fire' Boss on Fall Finale Cliffhanger and Leaving Dawson & Casey's Ending 'Open' (Exclusive)

Let's talk about the biggest moments from Wednesday's midseason closer.

Warning: Spoiler alert! Do not proceed if you have not watched Wednesday's season eight fall finale of Chicago Fire.

How is Kelly Severide getting out of this one?

The fall finale of Chicago Firetitled "Best Friend Magic," closed with a massive cliffhanger: the first-responder found himself cornered by a dangerous contract arsonist with plans to blow up the building and everyone in it. It was a classic Chicago Fire move, with the long holiday hiatus coming just in time for fans to obsess over how Severide will come out of this alive. 

Elsewhere in the episode, the surprise return of Gabby Dawson (former star Monica Raymund) didn't so much as provide closure for Dawson and Casey, but left even more questions unanswered for the estranged exes. Though Dawson's time in Chicago was brief -- she volunteered to return to her old haunts in order to see Casey one more time -- her feelings for her ex-love didn't seem to diminish at all. As the saying goes, absence makes the heart grow fonder.

So, what does this all mean? ET spoke with showrunner Derek Haas about the biggest revelations from Wednesday's fall finale, from Dawson and Casey's unfinished business (and the Brett factor!) to the season eight wedding to that crazy cliffhanger with Severide.

ET: How long in the works was Monica Raymund's return?

Derek Haas: We were planning it from the very beginning of the season. When I had written the scene at the end of the premiere episode this season, where Boden is dedicating this memorial to Otis and he says, "If you see somebody standing down here at this memorial, I want you to walk down this apron and bring the memorial to life." And just the image of Gabby from behind and Casey walking out on the apparatus floor and seeing her there, that's where it started. It was pitched right from the beginning and pitched to [executive producer] Dick [Wolf] and he liked the idea. So then I had to text Monica and beg her to come back again. She was like, "You're nothing if not persistent." I said, "Yes, that's true. I am. So come do it." We were thrilled that she did it.

Creatively, how fulfilling was it to have another Dawson chapter in the story?

Creatively, it's inspiring to get to write for Monica because you know she's going to make anything that you write for her better than what you had in your head. She's been like that the six years that I got to work with her. You sit down to your computer and you know you're going to get to write Dawson coming back. It was awesome. Then, of course, she was delightful as always on set. It's just so fun writing for her. I mean, writing for her is a blast.

There was a chance for closure between Dawson and Casey's relationship, but the door was left open. Why?

Yeah, I wanted to check in with her and see where she was in her life and what this year and a half since she left has been and get some answers that I've been asking, that the audience has been asking, for her. And then of course Casey... For me what was important is that they were both open about that she was only going to be back for a couple of days. Then, Casey finds out that, oh wait, she didn't get assigned to come back here. She chose to come back here to see you. We saw six years of their relationship and know what they meant to each other. For that, any walls that they had put up to melt down is perfectly within their characters, I think.

NBC

They spent the evening together after attending the charity gala. In terms of their relationship, how does this push them forward if there is another chapter to tell in their story?

I don't think either one of them is spun out. I think they both, if you'd ask them how the weekend went, they'd both be like, "It was great. It was great, actually." (Laughs.) Then, that voicemail that she gives him. I love this little smile that Casey has on his face when he's leaving the hotel and then appears again when he gets the voicemail from her. I think they're both willing to explore whatever this means going forward, in terms of, Drift into my life, I'll drift in your life and we'll see where it goes, because what they had was special and those kinds of bonds, they just don't disappear.

Dawson does extend an invite for him to visit her in Puerto Rico. Could we at some point see Casey take her up on the offer? 

Yeah. That would be fun to get to shoot something where he goes to a location that's in need of aid. That would be really fun to write and shoot. I will leave that as open-ended, as it was left in the episode.

It was great seeing Monica Raymund back in the world for a brief moment at least.

I love her. I'm happy for that door to be open and I would love to see her again. 

But then there's also the Casey and Brett factor... There is the moment when Brett tells Casey to go to the gala with Dawson and that he'd regret it if he didn't. Is she second-guessing that advice?

Brett is selfless and she always has been. Brett will 100 percent subdue her own feelings if she thinks somebody else is hurting or needs help or whatever their path to happiness is... She will put her own feelings aside so that they can move forward. That is who she is. That's how she's been since we first wrote her. In this situation, I think she had a front-row seat to Dawson and Casey even more than anybody else. I think she knows what this means and what the lack of closure meant to Casey.

She does have this look on her face right afterward, like she's not quite believing what she's telling Casey...

Well, Foster even says that. Foster's like, "Oh it was so, so good. That's so, so good to hear." So no, you're picking up on what other people in the firehouse are picking up on.

Will there be a point when Brett has to put her foot down and say, "This is what I want. I'm done being selfless. I need to be selfish." What is your take on her journey to reaching that place?

I think they're going to have plenty of opportunities to talk over their feelings in the next 12 episodes or 13, if we get one more. Their friendship's going to deepen for sure over the course of this season. Where it goes beyond that, I think I will withhold for now.

NBC

It was also nice to get a positive update on Antonio and where he ended up. Was it important to offer that nugget for fans?

When Dawson was coming, I figured it would be dumb not to mention Antonio since that's where they... He was leaving and so I had just walked down to Ricky's office and I said, "I'm going to have her say that he has joined her in the aid organization." And he was like, "Great!" So, that worked great. But don't forget, I lived with Antonio for a long time. I worked on that show for a long time. So, I was happy to do it. And I'm a hopeful guy. I like hopeful endings. He needed a mission in his life to get back on track. I was glad that he went there with Dawson.

Let's talk about the cliffhanger at the end of the episode involving Severide. He's kind of in a pickle...

Yeah, to say the least.

How is this situation different from all the other standoffs the Fire team has been faced with? 

The idea was we've done different arsonists on the show, but usually, they had some sort of mental health issue. So, we thought, "Can we do a different spin on an arsonist and do a contract arsonist, an arsonist for hire who's a cold, calculating, son of a b***h?" When you corner somebody like that, to me that's more dangerous than somebody who may not have all of their mental capacity. So, Severide down in a basement trapped with a guy who is a cornered rat who we know is a bad guy who was probably going to torch this place with everyone inside in it anyway. That is fraught with danger. We wouldn't be Chicago Fire if we let you go through Christmas without being worried for one of our characters.

How do you anticipate Severide gets himself out of this situation?

Severide isn't one to shy away from a confrontation. In fact, he would put his own life at risk to save someone else if they're going to be affected by that kind of a confrontation. What I do love about Severide is, he said this year, "I don't get nervous." Like, the guy messed with the wrong guy and Severide will sacrifice his own body to save someone else.

Can you say when the winter premiere kicks back up?

It starts up right away. We pick right back up with the scene, yup.

Since we're talking about Severide, I have to ask about Seager, who harbors a crush on Severide. Their dynamic has been very interesting to watch. What was your intention behind their flirty banter?

We love Seager. We just wanted a very competent, very confident lieutenant in OFI who was fun and cool. We kept referencing [The X-Files'] Mulder and Scully, like flashlights out and dust floating around them and in dangerous situations, but still having this easy banter between them. Severide -- we played all season and it's real -- only has eyes for Kidd, but I cannot find fault in Seager for being attracted to Severide. Who wouldn't sharing an office with Kelly Severide and watching him work? So, that's where I'll leave that.

NBC

Severide's been finding that he's actually good at his job at OFI. Is that more of a long-term position for him?

It's more attractive to him than it was a month ago. I think he thought it was probably sitting behind a desk and pouring over insurance reports. Then, he realizes, I can make a difference and I'm affecting people. He's always brought a level of danger to any job that he has. So, I think he's having fun and it's more interesting than what he imagined it would be.

In October, you revealed to ET that there would be a wedding coming this season. Can you confirm it's Cruz and Chloe getting hitched?

Yes, and I'm very excited about that. It won't be the season finale. That'll be somewhere in [episodes] 18 to 19 range. But we've done a bunch of weddings on the show and we always try to do something different and meaningful to the characters. The Chloe-Cruz wedding I'm very excited about and excited about writing towards that.

How is their wedding going to be different from previous ones we've seen?

That one you'll have to wait and see, of course. 

Severide is Cruz's best man. What sort of hijinks should we expect from them?

There's going to be a few misadventures. We wouldn't be Chicago Fire if everything went faithfully right from start to the finish. So, there's going to be a roommate shuffle going on that will affect Cruz. 

What awaits viewers in the second half of the season?

We're going to try and have a few more characters drop in from previous seasons as we go forward. I won't spoil any of that. I think Casey and Brett's friendship is going to grow closer. I told Dick that I want to get Olivia Benson on to Chicago Fire this year. That has not been approved by anyone other than me. (Laughs.) I would love to have Mariska [Hargitay] come to Chicago. We haven't done it. She's never been on Fire. She's been on P.D. I was throwing that out there, but other than that, you know us. We'll always have a lot of haymakers coming your way.

How would you describe these early episodes in 2020?

Dangerous, action-packed. Has there ever been a car chase on Chicago Fire? A firetruck chase? That's coming up. We have a lot going on.

Any more crossovers we can expect to see between the sister shows?

We're going to do one that's just us and P.D. like we did last year in the spring, but that hasn't been broken yet. 

Chicago Fire returns Jan. 15 at 9 p.m. ET/PT on NBC.

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