Leigh Whannell, most famous for making a movie — Saw — about a guy who hacks through his own leg in order to kill another guy, is a weirdly upbeat dude.

Or maybe it's not so weird.

Whannell, who wrote the depraved Saw, a few of its sequels, and the possessed-child Insidious horror movies, says horror movie people are usually happy people.

He knows this because he hangs out with other horror directors — Chelsea Peters (The Night Stalkers) and Mickey Keating (Ritual) and journalists like Sam Zimmerman of Fangoria, and Brian Collins of the blog Horror Movie A Day, or the folks at horror studio Blumhouse — who put the Oscar-winning Get Out on-screen — and backers of his new movie Upgrade.

"They're all happy people. I feel like it can't be an accident. I think it's something about catharsis, making horror movies, that must be healthy. You put all of your dark thoughts down on paper, and it's a means of expunging it from your life. You keep in it in a different universe."

Whannell is happy at the moment to be expanding he repertoire. His new movie, Upgrade is a set-in-the-future thriller about a paralyzed man named Grey (Logan Marshall-Green) who regains his mobility – and then some – when a tech titan gives him an artificially intelligent implant that reconnects his brain to his nervous system, and also enables him with heightened abilities.

Upgrade gave Whannell a forum to explore issues related to the (too?) rapid advance of technology.

"Grey is an analog human in a world that has become digital and computerized and robotic. He has a skill set [Grey is a mechanic] that has become obsolete. Everything's been automated. What he's good at is not required anymore. Nobody set out maliciously to do that to him, but that's what happened," he said.

Whannell has taken up science-fiction but hasn't given up gruesomeness. Grey is attacked by thugs and left a quadriplegic, and when the AI device gives him his life back, he goes in search of the culprits, now assisted by the Big Brain implant, which makes Grey omniscient and ultra-athletic, in addition to being ultra-pissed.

Problems arise, though, when Grey senses that the AI within his body may have an agenda of its own.

"Every vision of utopia makes something darker," he said, "something that was never contemplated at the beginning."

I mention that Upgrade is consistent with Whannell's other work; in Saw, Insidious, and Upgrade, characters surrender control through manipulation, possession, or usurpation.

"That's true. They're based on fears that I've always had. Fear of serious illness, of being incapacitated, losing consciousness, losing control. In my movies, I have a chance to explore those fears," Whannell said.

And he couldn't be happier.