There’s a new chief in charge of the fire department in NBC’s One Chicago universe. Dermot Mulroney joined the cast of Chicago Fire for its 13th season, which premiered on Sept. 25.

The beloved leader of Firehouse 51 for the first 12 seasons of the show got a promotion, making room for Mulroney’s character Dom Pascal to take over. Pascal seems cheerful on the surface and is eager to get in on the action, but his new colleagues are skeptical of his desire to shake things up.

Mulroney, known for his roles in beloved rom-coms old and new, including My Best Friend’s Wedding and Anyone But You, spoke with Yahoo Entertainment about his new gig, pop culture’s obsession with firefighters and his advice for former co-star Glen Powell on making fans happy.

This interview has been edited for length and clarity.

What can you tell me about this new character?

Dom Pascal has been working in Miami with fire rescue for around 10 years. When he comes to Firehouse 51, he’s the new chief in town. It’s been a decade or more since they had anybody new, so he comes in with an agenda — one thing on his list is not to make friends with anybody. He’s not concerned about that. He’s concerned about data points and putting out fires. He’s a pretty no-nonsense guy.

Why were you drawn to the role?

I’ve never played a firefighter and I’ve never been on an entire season of a network television drama, so I couldn’t ask for a better way of doing it. I’m not much of a “sit still” kind of guy in real life, so I match with Pascal on that. The writers seem to be leaning into Pascal being a full physical participant in putting out these fires.

Since your character is “replacing” one that was so beloved, did you feel any pressure to fit a certain mold for fans?

It is a challenge to make sure you don’t let anybody down, but most of that is up to the incredible writers who are cooking up amazing storylines. We’re building this character as we go — I have no idea what’s happening past [the sixth episode of the season] at the moment. But [Boden, who Pascal replaced] has been here a long time, so we’re not just changing the oil. This is like getting new tires.

You mentioned that Pascal is involved in putting out fires on the show. Were there any physically challenging scenes that stood out to you?

I’m training on the job, but let me tell you, there’s no better place to learn about firefighting. This place is packed with pros and veterans who run the whole fire safety department on the show. I know I’m in the best hands possible. They threw it all at me. All the special effects, stunts and background actors who are bloodied up and getting blown out of a window — it’s mind-boggling what they do on this TV show before lunch.

Many of the most-watched TV shows from the last year are about firefighters, like Chicago Fire, 9-1-1 and Fire Country. Why do you think people are drawn to this type of story?

I know I was drawn to them, and so were all the kids my age who were watching Emergency! It’s been a staple of television all along. They intend Chicago Fire to keep running on and on, and the way they cook up these stories — I know some of them are based on real incidents, but the rest of it, they’re just cooking it up out of thin air.

There’s no lack of ideas!

Right! Can I take a second and tell you what happened to me yesterday? I’m being driven by one of these teamsters to work, and I thought the company was shooting because I saw fire trucks and a squad pulled over. In fact, I was witnessing a real incident where a civilian car had run into the side of the engine. I couldn’t believe my eyes. The car wreck scenes I’ve been on twice in Chicago Fire look exactly like that. And let me tell you, they film in Chicago, and all the citizens are used to seeing Chicago Fire on the streets blowing up something. They’re pulling off the amazing scenes in public.

I admire the way you emphasize how important the projects you’ve been a part of are to fans — not just network TV, but romantic comedies. How did you come to the realization?

I really did mean it, and I’m glad that [Anyone But You star Glen Powell] has kept tapping into that advice. [My realization] came not just from being older, but from doing it longer. Veteran status and old age are different things! I had to have been in a rom-com that meant so much to people [My Best Friend’s Wedding (1997)] for so long to learn that. I’ll give this to Glen — he did it. He’s a tough guy. He put all of his heart and his love into that thing, and it’s going to pay off forever.

These One Chicago shows mean so much to people. You’re not just stepping into a role, you’re stepping into a dynasty, right?

Yeah! Anyone But You became this phenomenon, but on any weekend, a fraction of the people who watch Chicago Fire on a random Wednesday turned out for that movie. It’s staggering to me how network television comes to so many people. Long may they reign and get that many people to enjoy the same thing on the same night. It’s a communal experience that has a deep, lasting meaning.