The first thing we see in The 9th Life of Louis Drax, opening Friday (September 2), is a kid falling to his death. We’re informed by voice-over that our titular character is the most accident-prone kid in the world, the frame freezes mid-dive, and poor little Louis spends the rest of the movie in a comatose position somewhere between life and the hereafter. You’d assume this is pretty heavy subject matter for the 12-year-old who plays him, but no, it’s all in a day’s work for Aiden Longworth.

“I dunno, when I’m reading a script, I know I’m just reading a story. I wasn’t too frightened by it or anything,” he tells the Straight, in a call from home. Home, in this case, is somewhere in the area of Granville Island, where Longworth and his two siblings—Rowan and Hannah, also impressively busy actors—live an otherwise normal life. Aiden got the bug after spotting another kid from his housing co-op in a Hot Wheels commercial. “I saw him and I just thought it was so cool,” he remembers. Not too long after, Longworth had his own agent (“I thought it meant a spy or something like that,” he says with a chuckle) and his first credit, in 2012’s A Christmas Story 2.

These days, that résumé also includes Intruders and the recent X-Files reboot, but it’s a significant leap to Drax, an internationally financed feature production that also features Sarah Gadon, Jamie Dornan, Aaron Paul, and Molly Parker. Director Alexandre Aja is otherwise known for a string of expertly nasty horror flicks (High Tension, The Hills Have Eyes, Piranha 3D), so it’s no surprise that Drax, while anything but a screamathon, still traffics in elements of the fantastic. Longworth’s character, in fact, spends a lot of his screen time communicating with a Lovecraft-ian beast from the otherworld, as if Guillermo del Toro had been let loose on Heaven Is for Real.

“When I first read the script I thought that he was hilarious, because of his attitude,” Longworth says of the occasionally combative Louis, whose story is revealed in flashbacks to be a lot more complicated than we initially realize. “I think that he’s kinda clueless about what’s going on at first. He just really seems like an innocent child who’s being played, kind of, by his parents. I felt bad for him.”

Complementing what we learn from Drax’s supernatural encounters are the somewhat more mundane conversations he has with a child psychiatrist played by the great Oliver Platt. Predictably, Longworth says he learned a lot from the veteran film actor, whose scenes with Drax are easily among the film’s warmest. While the work of entering a character and staying there is “getting easier”, reports Longworth, Platt “makes it feel like he’s really who he is, which makes me feel like I’m actually there with him”.

Perhaps most endearing of all to a regular kid—who otherwise enjoys comics and raves about a recent viewing with his dad of Mrs. Doubtfire—is his 56-year-old costar’s habit of playing Tower Defense games on his phone between takes.

“I dunno,” says the clearly impressed Longworth. “I haven’t seen very many adults playing video games in front of me.”