For the first time in five years, all three One Chicago shows are ing forces for an epic three-hour event. The crossover airs Wednesday, January 29 and starts at 8 p.m. with Chicago Fire, followed by Chicago Med at 9 p.m., and ending with Chicago P.D. at 10 p.m. The official synopsis reads: "When a gas explosion rocks a high-rise, Chicago’s first responders come out in force to rescue hundreds of civilians. It’s the calamity beneath the surface, however, that sends our heroes on a race to save 40 people trapped deep underground, including two of their own."

While the episodes will feature reunions for several pairings, it will also see the franchise's main couples forced apart during the crisis. Ruzek and Kidd are trapped underground, with Burgess and Severide unable to reach their partners. Additionally, Platt is seen crashing in front of Mouch at the hospital. The personal stakes may further affect the team's ability to do their jobs, as the One Chicago showrunners tease that the separations fuel a great story.

ScreenRant interviews Chicago Med showrunner Allen MacDonald, Chicago Fire showrunner Andrea Newman, and Chicago P.D. showrunner Gwen Sigan about the crossover's main crisis, returning characters, and their favorite storylines.

Chicago Med Showrunner Allen MacDonald Wanted To Create A Satisfying Roller-Coaster Ride For Viewers

"I know that I was very interested in the character pairings that you can do on a crossover that are unexpected."

ScreenRant: What was most important for you to accomplish with this crossover?

Allen MacDonald: A satisfying roller-coaster ride of action, suspense, and emotion. I think that we're all pretty excited and happy with the results. We've obviously all seen it already, and it's good stuff. I know that I was very interested in the character pairings that you can do on a crossover that are unexpected.

At the beginning of the Fire episode, Dr. Frost is spending a day, for the experience, shadowing 51, and he works with Novak and Violet, which is entertaining to see their dynamic. There are just a lot of examples of that in the crossover of characters that you don't expect to interact.

How long has this been in the works?

Allen MacDonald: It was talked about pretty seriously as far back as March and April of 2024. It wasn't really decided for sure until about June, but once we dove into it, it was a train that kept gaining speed and very quickly each show chose a writer to work on the crossover and those three writers were like a mini writers' room.

They came up with the ideas that they pitched to Wolf Entertainment. Wolf Entertainment chose the ideas. The three showrunners, Andrea, Gwen, and myself—we had a lot of creative input, for sure, into the individual episodes, but those three writers were the frontline.

Will Goodwin be back in time for the crossover?

Allen MacDonald: Yes. She comes back, but because of her injuries from the fall finale and the surgery that happened in Episode 9, that Archer performed on her, she is coming back a little bit early, but when she hears what's going on, and that they're understaffed, she wants to be a part of the team.

How much will Sully’s death in Episode 10 affect Ripley in these episodes? Does the crossover stand apart, or is there a through line?

Allen MacDonald: It's both. These three hours are their own contained standalone story, but we don't ignore the fact that this is where these episodes fall in the chronology of the three shows. So, for instance, you'll see, when Ripley and Hannah arrive, they're dressed in black because they've just come from Sully's funeral. Maggie asks Goodwin, "What are you doing here? You're still recovering." And she's like, "You needed help. I'm here." Things like that, we touch upon.

We've seen Lenox lead the ER and keep her cool during a massive crisis, but how will she react when she is tasked with saving Platt along with the numerous others affected by the gas explosion?

Allen MacDonald: Yes. The Platt storyline is, to me, one of the main emotional centerpieces of the whole crossover and Mouch's reaction to it. And Lenox and Ripley are the ones that are working together to do what they can to save Trudy's life because it's not good.

And so it gives you a lot of opportunities for scenes that you weren't expecting. There's a very tense scene between Ripley and Mouch. There's a very tense scene between Lenox and Hank Voight. I don't want to go into what specifically the conversations are, but the reward of the crossover is seeing those moments.

Was there a character from either P.D. or Fire that you were excited to have back in the Med universe?

Allen MacDonald: I love everybody on the One Chicago franchise, but I have a soft spot for Mouch and Andrea Newman is aware of this, so she wasn't surprised when I asked, after the crossover, if I could have Mouch in Episode 15, which is a big episode for Ripley. I'm talking now about Chicago Med, specifically, but the dynamic that develops between Ripley and Mouch continues when we see Mouch on Med again in Episode 15.

Steven Weber compared the crossover to Avengers: Endgame. How would you describe it?

Allen MacDonald: I would say that Steven Weber is much better at soundbites than I am. You're not the first to ask that. I think the Avengers comparison, I hadn't thought of it, but it is actually perfect and there are some hero shots in the crossover—the characters all walking together from the different shows. In fact, one of them is at the end of the Med hour. But it is exciting to see all our heroes working together.

Chicago Fire Showrunner Andrea Newman Was Excited To Introduce New Character Dynamics

"The dynamics with those characters are really fun because there's a lot of fresh snow, as the expression goes, to tread on that we haven't seen before."

ScreenRant: What were you personally looking forward to accomplishing by bringing all these characters together for the crossover?

Andrea Newman: That's a great question. This one is really fun and there are a lot of new characters on the show, so to get to see these guys being introduced to the whole family as it were, it was really fun to see Pascal interacting with Voight and with Archer from Med. That was exciting and the dynamics with those characters are really fun because there's a lot of fresh snow, as the expression goes, to tread on that we haven't seen before.

Were there any characters you wanted to pair up, but couldn't because of time constraints?

Andrea Newman: We had so many people in this one. It feels like just one big movie. Really, everybody got to interact. It doesn't feel like a Fire episode, a P.D. episode, or a Med episode. It's seamless. They're all together throughout the three hours, so we really got to see a lot of these guys interacting, and it just makes you want more.

You see the other characters on the other shows and how well everybody goes together. We start automatically in the room saying like, "Okay, how are we going to bring Dr. Frost back? How are we going to get Burgess into an episode?" So it really starts conversations about the mini-crossovers as well as the big ones too.

Will this catastrophe test Pascal’s leadership skills and place in Firehouse 51?

Andrea Newman: Absolutely. It tests his leadership from his people to interacting with all the different frontliners that are on the scene there and seeing the leaders from the other shows like Archer and Voight going up against him in a way and how they have to all learn to work together and to save lives out there. So to see these big dogs all in the same room battling with their various leadership styles is a lot of fun.

Kidd is going to be trapped underground in the explosion. How is that going to affect Severide and his ability to do the job?

Andrea Newman: Yeah, I think that's always the biggest challenge, and it's seen before, and certainly Violet has faced before, is when you have to see somebody that you love in danger right in front of you, what that does to you, what it does to the relationship. This one is it really tests Severide's ability to keep it together and stay focused. He's rescuing civilians, and he's trying to get to his wife. It's a lot on his shoulders, and it's very emotional for him and for Kidd.

Will we see Severide and Burgess lean on each other since both of their partners are in danger?

Andrea Newman: That's exactly right. Ruzek and Kidd are trapped together and the little bit of communication that they get, in fact, a big moment is Ruzek ing along a message from Severide to Kidd that Burgess has given him. So they're all connected in this one. You're exactly right. Burgess and Severide are on one side of the wall, in a way, above ground, and the other two are below.

After all the drama with Junior, Cruz got away with only a two-week suspension in Episode 10. Will he be back at work when the gas explosion happens?

Andrea Newman: Cruz is suspended. He's on suspension, he's not there. That's the price he's paid as a character. He's been temporarily suspended. He'll be back, but he is not in the crossover. I think he's the one character that we don't have in this crossover.

What three words would you use to describe the crossover to fans?

Andrea Newman: It is cinematic, it is thrilling, and emotional.

Chicago P.D. Showrunner Gwen Sigan Hopes The Crossover Pulls At Fans' Heartstrings

"They're just a disaster movie that you're in, but it's also paired with a lot of emotion."

ScreenRant: What did you personally want to accomplish with this One Chicago crossover?

Gwen Sigan: I think these always work the best, at least it seems like it in the past, when they are huge scale. They're these big incidents and they're an action ride. They're just a disaster movie that you're in, but it's also paired with a lot of emotion, and you have some emotional hook to it and get to follow our characters in something that feels muscular and also pulls at your heartstrings a little bit. So that's probably the thing I was hoping that we would be able to find across the three hours.

Was there a duo you wanted to make sure had scenes when you first were planning it?

Gwen Sigan: You know what, I don't think there was because there were so many options, so I don't think there was any in particular. It was really fun to write some of the Ruzek and Kidd stuff because they did have a lot to do in our third hour. So that was one that was really exciting once we got really into the story and the breaking of it.

Speaking of Ruzek and Kidd, what can you tease about their dynamic since they're both trapped underground without their partners?

Gwen Sigan: It started to become clear when the writers started to get into breaking the story that all of these partnerships that have been so established on these shows all had so much conflict in them. We've got Mouch and Platt, and then we've got Severide and Kidd, and then we have Burgess and Ruzek.

So all of these partnerships and them all being separated and going through these things together, but also apart, made for a lot of great story and a lot of engine for us to continue. They'll all be affected by it quite heavily.

Allen MacDonald mentioned that the crossover is its own thing, but there are some through lines. With that being said, will we see how learning his father has Alzheimer's affects Ruzek?

Gwen Sigan: It definitely does feel like it's its own separate episode. It feels like it's just kind of like a movie thrown into the season. It's this big event. He doesn't have too much time really to deal with anything emotionally that has been happening during the season. But I'll say, it affects his headspace, obviously, right? He's already in a pretty stressful space when he comes into this episode.

And then, obviously, once all the events happen, he's placed in a particular situation where I think that being in a stressful place already and then having all these stressors thrown on top of you can certainly shake you up a bit. So I would say his headspace has been affected in this episode, but we won't see any of our serialized stories, necessarily, in this crossover.

What can you can tease about Trudy's plot?

Gwen Sigan: She's got a lot to do with this crossover. She's definitely got a big role to play in this thing. As you sort of saw in the promo, she does end up in pretty dire straits throughout the three hours, and it does become something that all the team has to rally around and becomes a bit of a ticking clock.

It helps us definitely raise the stakes for what's going on throughout the three hours. It's very emotional for her and for Mouch, and she's someone who's beloved by every single one of our characters, and also by everybody in the Fire world as well. I mean, she's married to Mouch, and so it's something that affects all of the characters throughout the three hours.

Out of all the One Chicago characters, who has your favorite storyline in the crossover?

Gwen Sigan: Ruzek's is pretty cool. Maybe him. And then I really like the new Chicago Med character, Frost. I like his storyline a lot as well. I think that that was a really nice one to write, and I thought it turned out really nice and emotional and real and grounded. I liked those two.

If you could have any past or present P.D. character team up with a One Chicago character, who would it be?

Gwen Sigan: I think it would probably be Voight and Casey and do some real throwback to the beginning of our season. His introduction on Fire was all about his storyline with Casey, so maybe that would be fun.

What three words would you use to describe the crossover to fans?

Gwen Sigan: Adrenalized, emotional, and action-packed.

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About NBC's One Chicago Crossover

From renowned Emmy Award-winning executive producer Dick Wolf

When a gas explosion rocks a high-rise, Chicago’s first responders come out in force to rescue hundreds of civilians. It’s the calamity beneath the surface, however, that sends our heroes on a race to save 40 people trapped deep underground, including two of their own.

Check out our other One Chicago interviews:

• Showrunner Gwen Sigan (Chicago P.D.)
• Steven Weber (Chicago Med)
• Joe Miñoso (Chicago Fire)

The One Chicago crossover begins Wednesday, January 29 at 8 p.m. ET on NBC.