If you have watched 9-1-1, one of the first things you may have noticed is the red birthmark on Buck's left eye.
In an industry where looks matter so much, it's unusual, not to mention refreshing, to see someone on screen whose face sports an interesting feature.
Oliver Stark, the London-born actor who plays Buck, says he was advised to have the birthmark removed.
"Somebody – an acting teacher of mine – did once say that to me," he says.
"I never really took it too seriously. People often kind of want to give you this compliment of like, 'Oh, you're so brave...' and I'm just like, 'It doesn't feel like that'. Because it's just never been one of the things I've been insecure about.
"So it's not like I'm going out there with this thing I'm really insecure about and carrying on anyway. It's never felt like that big of a hurdle to me.
"When I did first come out to LA, under the advice of some of my team at the time, I did used to cover it for auditions.
"Their thinking was they didn't want producers or someone to be watching an audition tape and lose concentration because they were wondering what's on my face. So I understood that. But then once it got to a certain point, it's just a part of me. I have no shame when it comes to that one aspect of myself."
That self-confidence served Stark, 28, well in the competitive and tough acting industry.
He is currently on screen as fireman Evan 'Buck' Buckley in 9-1-1, a US drama about a group of Los Angeles first responders.
For Stark, taking on the role of Buck meant gaining an understanding of what the job of a real-life fire officer entails.
"It's been really quite humbling and enlightening to just learn the kind of vast variety of jobs that they end up on (from) emergency calls that they have to take care of," says Stark.
"It's really amazing the kind of level of training that they need to have to be able to take care of so many different situations."
During the show's first season, Stark climbed 25 metres up a rollercoaster for a storyline where his character attempted a rescue.
"We have really excellent people around us who make it as safe as it can be," says Stark.
"If you're not comfortable with anything, you know that there are ways that they'll work around it. But for me, personally, that's one of the biggest perks of the job that I get to do these kinds of crazy things but in a safely created environment."
Stark says he can't recall wanting to be a fireman when he was a boy but says it is something he has considered in recent years.
"There was a time actually before I got this job (9-1-1) while I was living in LA and I wasn't really picking up much in the way of acting work," he says. "I lived opposite a fire station and I thought maybe I could do that (become a fire officer)."
Stark moved from his native UK to the US several years ago for personal as well as professional reasons. While he had appeared in short films and had guest roles on shows such as Casualty and Luther, his career had yet to take off.
"There was nothing I had happening at the time," he says.
"And actually, the truth of it is I moved because I had met a girl.
"It was like, 'I'm going to go and live with her'. That's the reason that I actually committed to the move and, thankfully, I've been able to find some work since moving here."
The 'girl' in question is American actress and model Hannah Harlow, who appeared on Project Runway.
"I met her on the internet which I suppose is a very modern way to do it," he says.
Stark is still with Harlow and his career is on the up thanks to the popularity of 9-1-1 which also stars big names such as established film actress Angela Bassett (Black Panther) and Peter Krause (Six Feet Under, Parenthood).
"I think it brings a real message of hope," he says of 9-1-1's success. "There's something very comforting in the fact that you're given this reminder that whatever it is, whatever situation you find yourself in, there are these people that will run into the danger to keep you safe."
