Change is never easy — especially for Buck.

In the 9-1-1 season 9 premiere, the entire firehouse was still reeling six months after the death of fire captain Bobby (Peter Krause). But those changes also created a waterfall effect that had Oliver Stark’s Buck feeling a certain way.

In particular, the firefighter spent much of Thursday’s premiere episode having what Stark previously described to Entertainment Weekly as “difficulty” with Eddie (Ryan Guzman) suddenly getting much closer to Hen (Aisha Hinds) as they partner up on EMT work, since Chimney (Kenneth Choi) is now acting captain of the 118.

Following the season 9 premiere of the ABC drama, Stark opens up to EW about the Buddie drama, Buck’s therapeutic moment with his baby nephew Bobby, and what’s to come in the upcoming episodes.

ENTERTAINMENT WEEKLY: How did you choose to interpret Buck’s issues with Eddie and Hen’s deepening friendship?

OLIVER STARK: I think it’s not from a malicious place. I mean, I know it’s not from a malicious place. But I don’t even think it’s from the same place that it would’ve been had this been two, three, four seasons ago. I think it’s just a compounding effect of Buck already being in a vulnerable place post-Bobby, and now something else that he’s used to is not feeling the same. You know, Buck loves him. He loves Eddie. He loves everybody at the 118. He’s more than happy for everybody at the 118 to be friendly amongst themselves. But just because everything else is feeling unstable, this is almost the straw that breaks the camel’s back for him. So yeah, he pokes fun at it, and he makes his feelings known, but he’s just struggling a little bit and trying to cling onto the things that he knows.

You teased a “vulnerable” conversation with a “maybe unexpected character.” That ended up being Buck’s baby nephew…

Baby Bobby! … I think sometimes we as people can be our most honest selves if we’re talking to somebody that you don’t feel like is gonna judge you back, and that’s not always the people that we are closest to. It’s not always a best friend. Maybe it’s a stranger at a bus stop who you end up telling things about yourself that you’ve never told anyone. In this instance, Baby Bobby is Buck’s stranger at the bus stop.

I think you’ve created a new tongue twister.

Right?! But he’s found someone he can open up and talk to and know he’s not gonna be judged for it, and he’s not gonna get advice that he doesn’t necessarily want. He can just spill, and there is another human on the other end, “listening” to him. And obviously Maddie [played by Jennifer Love Hewitt] is actually kind of is listening, but at least she’s not in the room. He is not having to look her in the face while he opens up about how he’s really feeling.

I’m really intrigued to see how the interplay between the space and the Earth emergencies carry out. They kind of complement each other. And we have some really fun, silly episodes. We have Halloween episode this year, which I know is a fan favorite. And I think there are some opportunities in episodes as we move towards the mid-season finale, where Buck really gets to take on a new role and dive into his different qualities as a firefighter: his leadership skills and his showing up for other people. He finds himself through helping others, and I was really excited to get to play that out.