7 Biggest Moments From the One Chicago Crossover

A disaster this big — a gas explosion threatened the structural integrity of a building and subway tunnel below — was never going to be contained to just one primetime hour. One Chicago's return to the crossover game played like a long movie, with very little to differentiate one hour from the others, and characters from all three series seamlessly jumping from one show to the next as if this three-episode event was merely an extended installment of one show. Chicago Fire's Season 13 episode "In The Trenches Part I" opened the crossover, which continued with Chicago Med Season 10's "In The Trenches Part II" and concluded with Chicago P.D.'s Season 12 episode "In The Trenches Part III," and when the dust settled, it felt like One Chicago had not only done a great job of celebrating these characters but also revitalized the franchise's idea of a shared universe.

The Dick Wolf properties had, after all, not done a crossover in a little over five years. The last time we saw a One Chicago crossover, the Halstead brothers were still around and at the center of both Chicago Med and Chicago P.D.'s storylines, and Matt Casey (Jesse Spencer) was still headlining Chicago Fire. So, the newest crossover didn't just have to deliver a good story, it had to re-establish the bonds between three shows whose only shared connection at this point was Platt (Amy Morton) and Mouch's (Christian Stolte) marriage.

But the "In The Trenches" crossover did more than that, establishing new dynamics that worked — including Hank Voight (Jason Beghe) and Dom Pascal (Dermot Mulroney), and Adam Ruzek (Patrick Flueger) and Stella Kidd (Miranda Rae Mayo) — and making sure that characters who had never interacted with each other not only met, but became familiar with one another in a way you only can during a shared emergency, with future implications. The next time the Chicago P.D. characters are at Chicago Med, they will remember it was Dr. Ripley (Luke Mitchell) and Dr. Lenox (Sarah Ramos) who saved Sergeant Trudy Platt (Amy Morton). And the next time someone at Chicago Fire needs police help, maybe the newfound friendship between Stella Kidd and Adam Ruzek can be an advantage.

More on One Chicago:

• Everything to know about Chicago Fire Season 13
• Everything to know about Chicago P.D. Season 12
• Everything to know about Chicago Med Season 10
• NBC winter TV schedule: Here's when your favorites return

Each show got its moment during the One Chicago crossover. But which characters stood out the most? Which dynamics worked? There were a lot to choose from, but here are the seven biggest moments from a crossover.

Lenox finds a way to help

Dr. Caitlin Lenox always felt like the kind of character who would have a hard time meshing with the rest of the One Chicago universe. She has, after all, had a hard time establishing rapport with her fellow doctors at Chicago Med. And she really isn't one to bend the rules, even when other lives are on the line. So when Voight and Kim Burgess (Marina Squerciati) asked her to wake up her patient — a possible suspect in the explosion — so they could get information from her, it was obvious she would say no.

After a conversation with Sharon Goodwin (S. Epatha Merkerson), however, Lenox found a way to help that didn't compromise her integrity. Or, at least, one she could live with. She gave Burgess enough information to identify the patient, which ended up being crucial to the Intelligence team cracking the case. So, Lenox might not have ended the crossover as anyone's bestie, but at least she ended up being helpful.

Ruzek and Kidd work together

For two characters who have been part of the One Chicago universe as long as Adam Ruzek and Stella Kidd have, the two haven't really had much in the way of one-on-one conversations before. But when the two find themselves trapped in a train underground after the explosion rocks the building and street above them, the One Chicago crossover forces them not just to talk, but to become unlikely partners in a situation that required them to work together to save their own lives and the lives of all the people they're trapped with.

It's not smooth sailing, particularly because they don't know each other very well, but they soon figure out how to help one another with what they each must do and how to be the partners they need to be under very complicated circumstances. The fact that they're stuck together also sparks some conversations between Kim and Kelly, who are waiting and worrying about their respective significant others. Could this be the beginning of a beautiful friendship?

Trudy Platt almost dies, and still saves the day

One of the most emotional moments in the One Chicago crossover comes after Trudy Platt is shot by an unknown assailant (who turns out to be Bates, a former police officer now working in security for the building that's at the center of the explosion). We see it happen and then we must watch the heartbreaking moment when the first responders drop everything to try to find her, only for it to be Mouch, her husband, who finds her bleeding out.

Then, as if that wasn't enough, we have to see her coding and almost dying before Dr. Ripley and Dr. Lenox take a gamble on a very experimental idea to save her. But Trudy doesn't just come through, she wakes up near the end of the crossover in good enough spirits to tell her husband to go do his job, and of course, to give Voight the information he needs to crack the case. Even after all she went through, Trudy Platt is still the one to save the day.

Archer steps up

Dean Archer (Steven Weber) has had a complicated time of late on Chicago Med. He was demoted as Chief of the ED after some time spent as co-chief alongside Lenox. Then, as he was about to resign, he ended up saving Sharon Goodwin's life, who then convinced him to stay. But there's no doubt that Archer is feeling a little bit like he isn't that important. The One Chicago crossover changes that by putting him in the middle of the action.

First, he walks Stella through how to save one of the people on the train she's trapped in. Then, he saves someone's life by making tough decisions in the field. Later, he volunteers to go down with the firefighters to help with the rescue, arguing they might need a doctor. It's a great episode for Archer as a character, but a particularly good one for his sense of importance to Chicago Med and the shared universe.

Kidd and Severide make time

Stella Kidd and Kelly Severide (Taylor Kinney) start the episode talking about whether they really want to take the long weekend and get away together, with Kelly arguing that they should wait until they have more time. Stella, meanwhile, believes with the kind of jobs they have, they must make the time if they want to do things. After Stella ends up trapped with Ruzek for most of the crossover, and Severide goes through the five stages of grief thinking he might never see his wife again, it all seems to click for him.

In the end, when everyone's finally safe and the two reunite, Kelly tells Stella they should get away. They can go wherever she wants. The two share an embrace and a kiss surrounded by ambulances and the bustle of the emergency they just survived. And, if this also makes them reconsider the idea of starting a family in the next few episodes, well… that's just the way life works.

Ruzek goes home to his family

Even though Stella and Ruzek are trapped with their lives on the line, Ruzek has full belief that he's going back to his family. He refuses to let Kim say goodbye and doesn't let her pull their kid, Makayla, out of school so he can talk to her. Instead, Adam assures them that he'll be home for dinner. Kim chimes in that they can have pizza, and Adam tells her they can have whatever their kid wants.

He ends up coming closer than he would have wanted to not coming home, but later, he and Kim reunite, just like Severide and Kidd do, though Adam has to go to the hospital, his fiancée is at his side. He gets to go home to his kid. Hopefully, the next step is the long-awaited wedding between the two that the show has been putting off for a while.

One Chicago showcases the courage of first responders

A lot has been said about the courage of first responders and the fact that they run into danger when most people run away. But if the One Chicago crossover does something right, outside of the character-focused plotlines, it's showcasing the courage of first responders, even if they use fictional characters to do so. The firefighters, paramedics, doctors, and cops in these shows rush towards danger to help, and that's a good reminder that in real life, there are a lot of people who do.

It's not perfect, and people in real life don't always get it right. The characters in the show don't either. But it's still very nice to see, nonetheless.

The One Chicago shows return to their normal time slots next week.