There’s something devious about the playfulness of Netflix’s Spiderhead. The sci-fi thriller, led by a dapper Chris Hemsworth, takes place at a remote prison slash research center, where inmates are given a surprising amount of freedom in exchange for being subjected to experimental pharmaceutical treatments that do everything from making them feel terrified to creating an impossible-to-satiate hunger. It’s bleak stuff. And yet much of the film has a light tone to help mask its devious nature; Hemsworth dances to ’80s pop, and inmates spend their free time playing arcade games and creating snacks with prosciutto and nectarines.

The whiplash between these moments and the dark premise is delightful, though ultimately, Spiderhead doesn’t quite stick the landing. It finishes with a fizzle — but it’s still a lot of fun watching Hemsworth try to dance along the way.

Spiderhead is based on George Saunders’ short story “Escape from Spiderhead,” first published in the New Yorker in 2010, and directed by Joseph Kosinski (Oblivion, Top Gun: Maverick), with the Deadpool duo Rhett Reese and Paul Wernick penning the script. Hemsworth stars as Steve Abnesti, an eccentric tech and science visionary who runs the Spiderhead Penitentiary and Research Center. The prison itself is located on what appears to be a remote island; the building is a daunting brutalist structure outside and looks like a vision of the future from 1975 inside.

Spiderhead has an open-door policy and seemingly no guards stationed. Inmates are all given jobs, like managing the snack output or serving as janitors. What really makes the place unique, though, is the little device implanted on the back of every resident. Each is full of a series of colorful vials containing different chemicals, and with a smartphone app, Abnesti can manipulate those chemicals to administer a specific drug and alter the state of the inmates. The first example you see is a man who simply can’t stop laughing; Abnesti starts by telling terrible dad jokes before eventually switching to reciting facts about genocide. But the giggles continue uninterrupted throughout the session.

There are drugs that make the inmates uncontrollably horny or hungry and another that turns any view into the most beautiful vista the person has ever laid eyes on. One drug turns a simple object — like, say, a stapler — into your absolute worst fear. As the prisoners experience the effects, Abnesti watches from behind a large glass wall, frequently giving out directions over a speaker. If the inmates aren’t especially talkative, he uses the app to give them a dose of “Verbaluce” to get them to describe their feelings.

The idea of treating a subjugated class as a kind of guinea pig isn’t a new concept in fiction, but Spiderhead differentiates itself with sheer audacity and its jarring tonal whiplash. The experiments are obviously disturbing, but it’s all hidden under a veneer of privilege and the illusion of choice. The inmates go along with it, even when it’s really messed up — at one point, a prisoner named Jeff (Miles Teller) is forced to choose which of his fellow inmates should get the worst mind-altering drug — because, well, it’s better than being in a regular prison. They also have to explicitly state they “acknowledge” the procedure before a dose can be given, making it seem like they actually have a say in the matter.

Holding everything together is Hemsworth, who you’ll absolutely want to punch in the face while watching this. He exudes tech bro privilege and optimism, masking his nightmare experiments under the guise of saving the world (from what, though, we’re never told). All the while, he berates his poor assistant and constantly makes the inmates feel like they should express gratitude for all he’s done for them. At one point, he jokes about how much he’s benefitted from looking so beautiful.

Spiderhead is a steady ramp-up of dread, moving from the laughing drug to some truly terrible “accidents.” It also does a great job at hiding its true intentions — when Jeff finally puts the pieces together and understands what the experiments are for, it’s an incredibly satisfying twist. Unfortunately, from that point, the film doesn’t quite know what to do with itself. There are some action sequences and chases at the end, but they all go largely nowhere. Spiderhead raises lots of fascinating (and depressingly relevant) questions but doesn’t really have much interest in answering them.

But up until that final act, Spiderhead works surprisingly well, like an episode of Black Mirror that has an actual sense of humor. It’s a story that shows how far you can get based on charm and the illusion of good intentions — and when you’re Chris Hemsworth, it’s pretty far indeed.

Spiderhead is streaming on Netflix on June 17th.