On NCIS: Los Angeles, Chris O’Donnell ran away from the explosions. Now, on 9-1-1: Nashville, he’s running right into the fire.

“It’s fun. It’s fun. I just saw it last night for the first time. I think people are going to really enjoy it,” he raves to TV Insider of his new ABC drama, on which he plays Captain Don Hart. “It’s always nerve-wracking, seeing something for the first time, because you’re like, ‘I don’t know what we just did,’ but we’ve been having fun and it really worked well and it moved and I think people are going to enjoy it. So, some surprises in there. It’ll be fun for people, especially the fans of 9-1-1.”

Below, Chris O’Donnell previews Don as captain and his complicated family life.

What kind of captain is Don? How is he as the leader of the 113?

Chris O’Donnell: Well, family is a big thing for him. Without giving away too much of the backstory, he didn’t have much of a family life growing up, and he’s married and has a son, but his family at the fire station is every bit as much a part of his family, to be honest with you. And really, the connection and the bonds that he shares with everyone who works with him, that is his life. Those are the people that mean the most to him. And so he’s protective of people, but he also, I think, wants to be a good leader and lead by actions as well as words and be inspirational to his team.

We know his family life is complicated, but it sounds like, despite everything, his and Blythe’s (Jessica Capshaw) marriage is solid. 

Yeah, I think that you’ll learn more about that, but he is not perfect, nobody is, and they’re at peace with the situation. But anything in life, there’s bumps along the way and ups and downs and we’ll have to see where this goes. But yeah, they’re all doing their best to keep the peace.

So there’s the matter of Blue (Hunter McVey) being Don and Dixie’s (LeAnn Rimes) son. How much contact has Don had with him, and how does he feel about the state of their relationship?

Needless to say, it’s a bit of a shock to him when he is finally face-to-face with him.

How is Don and Ryan’s (Michael Provost) relationship outside of this bombshell about his brother?

They’re very close. I mean, they’re pals. They do their rodeo riding together, and they work together, which I’m sure was a big decision. As you’ll learn, Blythe comes from a very powerful family, and I’m sure that there were expectations that he would aspire to great things and not necessarily, not that it’s not a great thing, but that he chose to follow in his father’s footsteps as opposed to all the opportunities that were probably showered on him I’m sure drives some people crazy, but that’s part of his love for his dad that has made him want to be following his footsteps.

What can you tease about how bringing in Blue into the situation changes Don and Ryan’s relationship?

Well, I mean, you got to put yourself in those shoes. Talk about a shocker, to find out you’re in your mid-20s, that you have a brother that you never knew of, and that your parents have never spoken of is a bit of a shock, to say the least. So I think there’s going to be some damage control we’ll work on there.

How good are they at compartmentalizing the family stuff and then the professional when they’re on a call when it’s life and death?

I think that once people get over anger and shock and give people a chance to explain themselves if there’s valid reasons or explanations for things, I think people can be more understanding or as opposed to something that was maybe just reckless and is hard to explain. So hopefully they can work things out.

What can you say about Don and Dixie’s relationship in the past and in the present?

They have a lot of history, which it’s funny, we’re about halfway through the season filming it, I just learned a lot about that history recently. But there is a long history and there was a real bond there and she has been a big part of his life.

What about in the present? Is that a threat to Don and Blythe’s marriage, and if so, how much?

Well, we’ll have to see.

There’s clearly this rivalry between Blythe and Dixie that we’re getting tastes of in the promos. Can you say how much that is about who Don is to them, how much that has to be about having to be in each other’s lives because of Blue and Don, and how much it’s something else that we just don’t know?

I think that when someone’s chosen or not chosen, that hurt can take a long time to go away. I think that nobody likes to be spurned or second choice to somebody, and so I don’t know, that can be a tough thing to kind of bounce back from.

The trailer hints at Blue and Dixie having some sort of plan. What can you say about how much Don trusts Blue at the beginning of the series?

I think he does as much as he can. I mean, he really wants to because I think that there’s a lot of regret that he hasn’t been a bigger part of his life all these years, and so he’s hoping for the best. But again, this is someone that, it’s a grown man that he doesn’t know here, so he’s dealing with that.

Who’s the bigger blind spot for him, Ryan or Blue?

Well, there’s no blind spot for — I mean, he knows Ryan every inch of Ryan and knows him well, but this is a lot, this news is a lot for anyone to digest. So it’s something that’s been weighing on him. He knows this day was going to come. He knows this is something he was going to have to face and it’s been eaten away at him. And I think that there’s almost a moment of relief for Don that is dramatic as this is, it finally came to a head. I think a lot of people that live with secrets, it can eat ’em alive and sometimes it’s best to just bring things to a head and get it over with and let the chips fall where they may.

Disney/Jake Giles Netter

What can you preview about the first major rescue of Don’s that we’ll see on screen?

It’s very musical. It’s very windy and rainy. There’s a lot going on.

But Don is the type to be the first one to leap into action?

Well, he is their leader. He’s got to lead them into action and direct traffic, so to speak. It’s all part of the team. The captain’s there to kind of direct traffic, tell people where to go. But sometimes there’s moments where the captain has to step up and really get into mix and lead the charge.

Music is very much part of the show. That’s something new from the other 9-1-1s. Will we see you singing?

Not that I know of. [Laughs] Let’s hope not.

Would you be open to it?

No, I’m going to let — there’s some really good singers in this crew. I’m going to let them handle that.

There’s this big firenado kicking off 9-1-1: Nashville. What can you preview?

Yeah, I didn’t know it was actually a real thing, to be honest with you. I was kind of laughing. I was like, “What the hell is a firenado?” And they said, “Yeah, look it up.” And of course, there are the videos on YouTube, like everything else and filming down there, living down there, it’s some serious weather, I have to say. I mean, I’ve seen more lightning and storms come through in the short time we’ve been there than I have in years. We just don’t get that in California. But yeah, I think I would duck and cover if I saw a firenado coming.

9-1-1: Nashville, Series Premiere, Thursday, October 9, 9/8c, ABC