Another season of 9-1-1 is in the books, and to celebrate, Decider sat down with Oliver Stark to unpack Buck’s final two episodes, revisit some Season 9 highlights, and look ahead to Season 10.

Before Season 9, Episode 18, “Hearts and Flowers,” aired on May 7, Stark stopped by Decider’s Midtown Manhattan studio to discuss Buck’s reunion with his biological son Theo (Lincoln and Theodore Sykes). We chatted about a potential ADHD diagnosis for Stark’s character, parallels between Buck and Eddie’s (Ryan Guzman) stories, and how the single dad will play a crucial role in Buck’s new chapter. But before the 9-1-1 star closed the door on Season 9, he reflected on a few favorite episodes that were particularly fun to shoot and challenged him to step outside his comfort zone.

“It might be the same answer for both. The one that comes to mind is the auction,” Stark said, referencing Season 9, Episode 11, “Going Twice.” After 9-1-1 established Buck as the former star of the LAFD Bachelor Auction who once inspired a bidding war that ended in a $8,001 payout, Buck threw his back out and got insecure about his age ahead of the big charity event. When it came time to walk the runway, he ultimately captivated the crowd with a killer multimedia presentation and some high-energy stripping. But while Buck regained his confidence, Stark struggled to find his own when filming.

“That was so difficult for me to come out, rip the shirt off, be twirling it around. To be that guy? That is not my nature. I’m quiet. I’m contained. So it was quite difficult to step into that. And it was one thing in the first couple of takes when we were allowed to have noise, so there was music playing and the crowd was going wild. That carries you through. But then for sound reasons, all of that had to go away. So there’s no music. The audience has to mime, they’re not even clapping. They’re doing silent claps and they’re just pretending to scream. And I’m prancing up and down that runway and acting like I’m having the time in my life. It was so awkward,” Stark recalled.

“It was really challenging for me. Literally before I came out each time I would say to myself, ‘Just be the guy. You’ve got to be the guy,'” the 9-1-1 star recalled. “But then because of those difficulties, it was also extremely rewarding once I did get into it. And honestly, the last take, I knew they had the sound. So I said, ‘Can we bring the music back?’ And that take felt really, really fun, because I was out of the awkward moments and able to just embrace it.”

From an emotional standpoint, Stark shouted out Season 9, Episode 15, “Pick Your Poison,” as an impactful favorite. The episode saw Buck struggle with a dependence on pills, which he managed with help from his loved ones. “The montage stuff that we did at the end and getting to be a part of constructing all of that, I really loved it,” Stark said, stressing that watching the characters come together in support felt like perfect embodiment of the show’s message. And of course, a Season 9 favorites list wouldn’t be complete without the Misery-inspired Episode 13, which saw Buck and Eddie’s road trip home from Nashville go very very wrong.

“Obviously, the episode out in the desert was so rewarding in a sense that it just felt like it was a different show. It was shot in such a different way,” Stark said. Back in March, Decider broke down the ambitious installment with showrunner Tim Minear, who passionately spoke about exploring Buck and Eddie’s dynamic in “Mother’s Boy,” working on location with his longtime pal/director Jonathan Lawrence, and Stark’s “fantastic” performance.

“One thing that really came together for me in the episode, there’s a moment where Buck is trying to escape and Bonnie (Melinda McGraw) comes in and ends up prodding him with the cattle prod, and he kind of gives over in that moment and says, ‘I’m Derek, I’m Derek, I’m Derek,'” Stark shared. “That was a scene that was constructed already, but her coming in and prodding him again, Tim came up with that on the day — the morning of. I didn’t know that ahead of time for whatever reason. Maybe I went to bed early the night before, but I hadn’t read those pages. So we were in rehearsal, and I had learned what I knew the scene to be. And they’re like, ‘No, no, no, those are the old lines. These are the new pages.’ So that just came together for me then and there. And I called Tim afterwards and I was like, ‘I love this.'”

Throughout the past nine seasons, Stark has given his fair share of powerful dramatic performances, but he loves an opportunity for the show to enter even bolder territory. “It’s so dark that she does that. And you can interpret it two ways, you could say that it breaks Buck’s mind a little bit there, or he just gives over. But either way it’s super dark,” Stark said. “I was really happy that stayed in with the intensity that it did, because I do think that’s pushing the envelope on network TV, of how deep, and dark, and intense you can go with it. That’s a favorite moment from the episode for me.”

Back in Season 7, after filming a big karaoke scene with Guzman (which was ultimately cut, RIP), the 9-1-1 star told me, “I hate karaoke…like genuinely. No exaggeration. Karaoke is my biggest fear in the whole world. You can put me in a harness and hang me off the side of a building on 9-1-1. Fine. You’re writing a karaoke scene, and I am nervous. Really, really nervous.”

Though Stark revealed he recently braved the karaoke stage in real life and had a blast, back then, he said he would “literally rather leave a venue than go up on stage” and that he needed “a little bit of real tequila flowing on set” to help him shed his inhibitions before filming the Season 7 scene. Naturally, two seasons later, I had to check in to see if Stark experienced that same fear when singing “Carry On Wayward Son” in the car with Guzman in “Mother’s Boy.”

“No. For some reason I didn’t. I’ll tell you why, because the biggest fear with the karaoke was having an audience watch me do it. So at least this was in a contained situation,” the 9-1-1 star explained, revealing had other things to worry about, like the song lyrics!

“What’s funny about that scene to me when I watch it back is it’s so obvious that I don’t know the words. So I’m in a passenger seat, Ryan is driving. And on the dashboard we actually taped the lyrics, because we didn’t know them, and we hadn’t spent enough time learning them,” Stark revealed. “There are moments I can see myself reading the lyrics and still messing it up, which I think is fine, because in karaoke you don’t always know the lyrics and you kind of just fill in the blanks. I think us not knowing the lyrics actually helped it feel more relaxed for me. When we did the karaoke scene a few years ago, I was like, prepping. I was ready. For this one it was just like, throw it out there, let it be whatever it is.”

After fans go back to rewatch Buck and Eddie’s singing with that new context, it’s time to look ahead to Season 10. In our first article, Stark teased a trying time as Buck tries to navigate the foster system and the show explores why he’s the one caring for Theo. “It will be interesting to see what the work/life balance is for Buck. Whenever you have kids around you, it’s such a mirror. You learn so much about yourself,” he said. “So I think Buck figuring out a lot about the person who he is through somebody else and through this mirror of a child is going to be very prominent.”

When looking back on Season 9 with Decider, Minear revealed he brought back the sperm donor storyline because “It just felt like it was time” and “Buck needs someone new to love.” So does that mean a Season 10 love interest is out of the question? Not necessarily.

“I think that all his choices would be governed by having that kid. That’s going to alter how he looks at everything. So I think that’s interesting,” Minear said. And Stark echoed the idea that Buck will reevaluate and be more intentional about his approach to dating with Theo in his life. “It’s another, not obstacle, but something else thrown into the mix certainly when considering a partner,” Stark said. “I think if there is to be a partner for Buck and if Theo is going to stay in his life, then it would have to be a partner that fits in with that and is somebody who you would be willing and you’d trust to have around a child.”

When asked what love looks like for Buck, Stark mused, “I think love is such a big part of the show. Platonic love, romantic love, the love of the 118. I think it’s showing up for each other, being there without being asked. And for Buck, the lack of contingency placed on love is big. With his parents, for example, we saw that love was only contingent on him being useful. So for Buck, he values the kind of open, free love not based upon or contingent upon anything that one has to do. Just a natural, safe, freely given love.”

We know we’re getting Buck and Theo, Detective Athena (Angela Bassett), and Nurse May (Corinne Massiah) when the series returns this fall, but if 9-1-1 has taught us anything it’s to expect the unexpected. Ten season in, Stark’s still down to play and push boundaries. In trying to come up with an especially wild storyline for Buck we thought back to Shannon’s Season 7 doppelgänger episode and asked if Stark would be down to play Buck’s doppelgänger using his own accent. “Like super British. Yeah, yeah, yeah. 100% I would love that,” he laughed. “And now if this is in the show, it ain’t my fault.”

While Stark waits for hiatus to end and scripts to be written, he’s feeling lots of gratitude around the upcoming milestone. “We’re going into Season 10, it’s pretty amazing to me that there are fans that have been with the show for so many years. So I thank them for watching all this time and I hope they enjoy what we serve up,” he said.

9-1-1 Season 9 is now streaming on Hulu.