LOS ANGELES — Jack Quaid is that guy — we all know someone like him — who convinces you that the haunted house will be fun. “You can be very prepared” for the scares around each corner, he’ll say, reassuringly. It’s an “immersive experience,” he’ll say.

Then, on a recent Saturday night, you, along with Jack and his girlfriend Lizzy McGroder, an actress and comedian, will check out the Halloween Horror Nights at Universal Studios, a journey through 10 spooky mazes inspired by the studio’s films and TV shows, and it will scare you half to death.

And you’ll know that what is thrilling to Mr. Quaid, 27, star of the Amazon series “The Boys,” is downright heart attack inducing.

Mr. Quaid grew up in Santa Monica and lives in Los Angeles, but he has been spending a lot of time in Toronto, where “The Boys” is filmed. The show takes place in a world where superheroes not only exist, but are also deeply flawed and marketed to the general public by a corporation called Vought International.

Mr. Quaid plays Hughie Campbell, a store clerk who joins a group of non-superpowered vigilantes seeking to take down the superheroes because his girlfriend was killed by one of them in an accident.

The son of Dennis Quaid and Meg Ryan, Mr. Quaid traces the origins of his acting career back to a middle school production of “A Midsummer Night’s Dream.” (He played Nick Bottom.)

“I always saw my parents do it and I’m like, ‘O.K., they’re having fun, but do I want to do this?’” he said. Once he tried it, he recalled thinking, “‘O.K., I got bitten by the acting bug, let’s do this.’”

After graduating from New York University, Mr. Quaid acted in short films, played a minor character in “The Hunger Games: Catching Fire” and had a recurring role on “Vinyl,” an HBO show.

This year has been something of a breakout one for him. In addition to his role on “The Boys,” he played the leading man in “Plus One,” a romantic comedy about two single friends who agree to be each other’s wedding dates. It came out this summer.

At Universal, where the night began with a V.I.P. van tour of the studio’s back lot, Mr. Quaid filled a different role: movie nerd. The group’s tour guide, Chris Maul (“like Darth Maul,” he said), pointed out iconic sets, including the Bates Motel from “Psycho,” Whoville from “How the Grinch Stole Christmas,” and backdrops for “Waterworld” and “Jaws.”

When the tour passed the city hall set for “Back to the Future,” Mr. Quaid started geeking out. Mr. Maul offered to pull over so he and Ms. McGroder could take pictures.

“Jack, you’re like a kid,” Ms. McGroder said.

“This is like legitimately the best night of my life,” he said.

Then things got scary.

First, it was the Frankenstein Meets the Wolf Man maze, conceptualized around a scenario in which the two Universal Studios monsters encounter each other in a cemetery; the guests walking through the maze are caught in the middle of it. The experience included many grotesquely costumed figures popping out from behind curtains without warning.

Mr. Quaid led the way with Ms. McGroder holding onto his shoulders. He plugged his ears and parted the drapes between sections of the maze with his elbows. Despite his and Ms. McGroder’s encouraging words to this reporter and a P.R. representative for Mr. Quaid, who was also in attendance, there was a lot of screaming.

The “Ghostbusters”-themed maze offered a change of pace before everyone was thrown back into a state of terror in the Creepshow maze and the All Hallow’s Evil outdoor experience.

Mr. Quaid and Ms. McGroder have a quirky meet-cute story. Mr. Quaid was getting drinks with friends at Harvard & Stone, a bar in Hollywood, when Ms. McGroder started yelling nonsense at him.

“All of a sudden, from across the bar, I just hear, ‘Hey! You! Get over here. You’re late. Mom’s going to cancel the trip to Mexico,’” he said. Ms. McGroder, 28, does improv and sketch comedy as a member of the Groundlings Sunday Company.

Mr. Quaid, who was a member of Hammerkatz, an improv troupe at New York University, just rolled with it. “I was like, ‘Yeah, sorry I’m late,’” he said.

The couple recently modeled in an ad campaign for Frances Valentine, a New York-based accessories line founded by Kate Spade; her husband, Andy; and their friend and business partner Elyce Arons.

“She gave me so many tips,” Mr. Quaid said of Ms. McGroder. “I was like, ‘How do I angle my body to sell clothes?’”

They love collaborating, whether it is on goofy social media posts or video shorts. (Mr. Quaid stars in a short Ms. McGroder helped write, in which a fictional star of “The Bachelor” has a dark encounter with fans.) “Our ideal Friday night is getting ice cream and watching ‘The Bachelor’ franchise,” Ms. McGroder said.

On their way to take a dinner break, the two walked through the Scare Zone, where they were accosted by, among other horrors, a zombie on stilts and masked men with chain saws.

“We love the interactive horror stuff that really, fully immerses you,” Ms. McGroder said. “I like anything that makes you believe you’re in a dream.”

More like a nightmare. “Maybe you’ll like actually like this, the taste of it,” Mr. Quaid said to this reporter. “I was like that once when I was like, ‘No, I’ll never go,’ and now I really love it.”