The first thing I wanted to do after seeing Steven Soderbergh’s Unsane was to binge every scrap of art that’s ever featured Claire Foy: The Crown, Wolf Hall, Little Dorrit—all of it. Here’s an actress who feels distinctly alive, whose every instance of peering right into the camera (which can happen frequently in a paranoiac thriller) irreversibly destabilizes your sense of who she is and what she’s thinking. It’s a bracing, alchemical mix of complete candor and clockwork mysteriousness, like she’s figuring out her character just one step ahead of us and shredding all the evidence to throw us off her trail. Good actors know how and when to unleash their secrets, and they rise to the occasion of our expectations accordingly. But great actors find ways to tease you with those secrets. They upset those expectations.

Foy is a great actor. In Unsane, she plays a woman named Sawyer Valentini, which is the kind of name a Tinder date can’t help but remark upon, because it’s so unexpectedly exotic for a character being played by an actress named Claire Foy. Early in Unsane, Sawyer goes on a date with a guy who, in addition to quipping about her name, tries a little too hard to get laid. Sawyer cuts him off. “Tonight’s gonna go how you want it to go—no question,” she says. “But afterwards, you don’t call me, you don’t try to be in contact.” Well, OK! The date doesn’t go as planned, but you probably figured as much. The mystery is in the why. As soon as they start making out in the corridor of her apartment, Sawyer gets spooked and locks herself in the bathroom. Later, we see her Googling support groups for stalking victims; soon after that, we see her confess to a therapist that she’s occasionally considered suicide, having had her life upturned by a man named David Strine (Joshua Leonard) who’s stalked her so consistently, despite a restraining order, that Sawyer was forced to move to a new city and cut herself off from her former life. Troublingly, on the basis of that account, Sawyer gets involuntarily committed to a mental hospital. And soon after that, we meet her stalker.

Or do we? Unsane is, yes, that kind of movie: paranoid as all get-out, with a quick opening procession of scenes that make you go, “Damn. Damn. Damn!” Good. The script, as smartly written by James Greer and Jonathan Bernstein, knows what it’s doing to your expectations. The movie shifts from being a straightforward escape thriller about every therapy patient’s nightmare—having your doctor use your confessions against you—to making us wonder whether Sawyer, who seems to see her stalker’s face everywhere, might really need substantive help, to braiding those two threads into one tense experience. You root for her as you worry. Maybe you even question whether what Sawyer thinks she’s seeing in the hospital is real. But that soon subsides. Crucially, either way, the movie never presses you to question Sawyer’s fear.

Instead, we roll with it. The movie rolls with it—in part because that’s simply the most entertaining, unsettling angle it can take. Unsane is a genre film beefed up with the usual Soderbergh hobby horses—the deception of institutions, the circulation of information, the process of it all—but rather than crowd the story with meaning, it all recedes to the edges of the movie. Suggestions of a subplot about corruption offer up pinpricks of higher stakes, giving you something to Google when you get home while never letting the movie uncomfortably ascend to some kind of social document. Soderbergh doesn’t make those anymore. But yes, there’s a ProPublica article buried in here somewhere about the scamming of the insurance industry, and a late twist featuring a journalist that for some viewers will recall Samuel Fuller’s classic Shock Corridor (1963), about a reporter whose foray into a psych ward inadvertently distorts his own sense of who he is.

The same happens to Sawyer, in a way, who makes one friend (played with welcome benevolence by Jay Pharoah) and one enemy (a harrowing Juno Temple), and who all along just wants to figure out what the fuck is going on. Unfortunately for her, you can’t trust anything about this film, certainly not the directorial sleights of hand of Soderbergh himself, who, knowing that audiences rely on a movie’s tone to tell them how to feel, instills Unsane with a bone-deep sense of uncertainty.

Funny, though, that what makes Unsane headline fodder isn’t any of that, but the fact it was filmed almost entirely using iPhone cameras. We keep saying Soderbergh “shot it on an iPhone” as if he pulled out his phone and started filming candid 15-second snippets of mayhem for his Instagram Story, unbeknownst to his actor friends. We say it like it’s somehow a haphazard, improvisational process, rather than a skilled, thoughtful one. Unsane is quick and dirty, but not that quick (though maybe that dirty). Back in 2014, Sean Baker, the director of last year’s wonderful The Florida Project, shot his breakout feature Tangerine on three iPhone 5s, and it was overwhelmingly considered to be a big deal. But there have been multiple black-turtlenecked (in spirit, at least) Apple announcements of the iPhone camera’s advancement since then—and clips from Unsane would make a worthy addition to the Apple commercial highlight reel, though not because they’re classically beautiful. Even better, they’re giving a virtuosic sense of what these tools can do in smart hands.

I’m pretty into the way the movie looks, but don’t tell anybody—not a popular opinion. For me, the three iPhone 7s Soderbergh used to film it, spruced up with Moment lenses, and the familiar, precisely controlled two-tone color palette bear the mark of someone actively trying to fashion the iPhone camera into a viable, dynamic alternative to expensive movie cameras. And not just for low-budget indie upstarts like Baker, by the way, but for big-name Hollywood directors, too. It’s funny how quickly iPhones became the handy, omnipresent avatars of, say, citizen journalists and Instagram starlets, while so infrequently seeming to catch on with quote-unquote serious artists as a viable tool. That isn’t solely what makes Unsane an invigorating project, but of course for an industry in flux, the creativity of his approach matters. This isn’t just an experiment: It’s an argument for a new direction for Hollywood filmmaking, deceptively cloaked in the B-movie trappings of a movie that knows it doesn’t “matter.”

I should say that Soderbergh has bragged about the image quality of the iPhone. (“People forget, this is a 4k capture,” he told IndieWire in January. “I’ve seen it 40 feet tall. It looks like velvet.”) Yeah … no. I think he’s setting himself up for failure, on that front. At the very least, can we reserve a descriptor like “velvet” for images that don’t make skin look so splotchy? He’s of course right, however, to suggest that the pleasure of these images is in their flaws. Unsane is at times an adamantly ugly and convincingly cheap-looking movie, and better off for it, because when Soderbergh really takes off—when we careen through empty hallways with Foy, or spy on her from a voyeur’s distance—the director’s manipulation of his images feels electric. It makes the movie feel truer to the low-budget genre thrills it has up its sleeve. More than that, it makes the images look familiar, of our own world. We all know by now what an iPhone camera is capable of, what the videos look like. Seeing that familiarity contorted into something nightmarish, paranoiac, and ugly is deceptively thrilling. Soderbergh is speaking our language, but he’s using it against us.

That’s all a long way of saying: Soderbergh’s gonna Soderbergh. This is the same dude as always, or at least the one we’ve been getting of late: the director who’s turned what other directors of similar clout and talent might consider side projects into a full-on, hyperactive stage of his career. “There was no scenario in which I was going to un-retire and make a movie that wasn’t fun,” he told GQ last year. “I would not have come out of retirement to do something ‘serious’ or ‘important.’ No way.” Movies like The Girlfriend Experience, Contagion, Haywire, Side Effects, Magic Mike, Logan Lucky, and now Unsane may vary in achievement (frankly, I think they’re all exciting) but they all share a lightweight, offhand quality that in another director’s hands might feel openly inconsequential. The story for Soderbergh is that his last “big” project, the two-part Benicio Del Toro–starring Che (2008), killed his interest in studio-size ambition. So he’s reverted to making films that can feel like prix-fixe appetizers. They’re ostensibly not big swings or decisive turning points in his career. They steer clear of an overt sense of “importance.”

I dig that. I see the same seething intelligence in these movies that Soderbergh displayed in his bigger Hollywood hits—Traffic, Erin Brockovich, the seminal Out of Sight—if not more intelligence. You sense freedom in the way Soderbergh has doubled down on his style. You can tell that he’s making it look easy because, in fact, losing the big Hollywood apparatus has genuinely made making movies easier for him. In Unsane, Soderbergh hits us with more of his trademark, angularly intelligent images. It seems he can’t help but make even innocuous-seeming scenes feel analytical, pivoting at hard angles through an exchange between characters like an appraiser watching the proceedings through a jeweler’s loupe, measuring integrity and worth. You sense this as early as an opening scene in Sawyer’s office, during an exchange with her boss that reeks of sexual harassment. Another director, seeing an opportunity to dramatize Sawyer’s clear discomfort, would home in on the ugliness of the harassment itself; Soderbergh, playing up the staging and editing to play hype man to Foy’s exceptionally perceptive performance, instead makes it a scene about Sawyer’s inner sense of calculation. She doesn’t suffer the moment: She navigates it. It’s an early sign of how she’ll wind up navigating the continual deceptions and horrors of the entire movie. She is a genre movie heroine who’s always thinking. Call it experience: Remember, she’s had to wiggle her way free of unwanted attention before. What she’s thinking, and how she acts on those calculations, becomes the story.

Is that too intellectual for a dumb B-movie? I don’t think so—I think it makes the movie more surprising at every beat. But we know by now that Soderbergh sometimes leaves audiences cold, or rather leaves them with the impression that he sees his characters with an enduringly skeptical sense of distance. I can’t promise that people won’t feel the same about Unsane; I can only promise that they’re wrong. Unsane is easy to treat like a parlor trick, a movie more interesting for how Soderbergh is trying to disrupt the Hollywood system than for how entertaining it is. But it’s Unsane’s allergy to bigness that liberates it. Foy turns in the kind of genre performance that isn’t available, not among movies made by talented directors, for actors of her caliber as often as it should be. Wouldn’t it be great if every actor as sharp and alive in 2018 as Sharon Stone was in 1992 were given a Basic Instinct to play with? Unsane isn’t as canonical as that—I won’t exaggerate—but it made me miss that lane of movie. It’s a real-deal movie with a real-deal star turn, and—per usual—Soderbergh makes it look easy.