Steven Soderbergh’s “Unsane” introduces us to Sawyer Valentini (Claire Foy), a youngish woman who has moved from Boston to nondescript Pennsylvania. She’s settling in, but not comfortably: Sawyer has sharp edges, a jumpy energy, a whiff of toxicity. She brings home a man one night, comes on strong, then reels away from him as if punched.
After seeing a therapist to complain of anxiety — an understatement, we’re thinking — Sawyer signs a few routine-looking papers. Then, as nurses and orderlies calmly close in on her, she realizes she has committed herself to Highland Creek, a psychiatric ward. “You can see I don’t really belong here,” she coos to an administrator. Like us, he’s skeptical.
That’s only the beginning of “Unsane,” which proceeds, in 98 fast-paced minutes, to pull Sawyer through a labyrinthine nightmare — and us along with her. It’s a terrific thriller with a finely calibrated performance from Foy, shedding her kid-gloved role as Queen Elizabeth on Neflix’s “The Crown” to play a damaged, prickly, ferocious American. She’s joined by a couple of other fresh faces: Jay Pharoah, of “Saturday Night Live,” as a man kicking an opioid addiction — or so he says — and a very good Joshua Leonard (still best known for “The Blair Witch Project”) as an unctuous Highland Creek orderly. The less you know about the story, though, the better. Much of it relies on our distrust of Sawyer and then, once we know where we stand, “Unsane” takes on the feverish, desperate feel of a rat clawing at its cage.
“Unsane” is Soderbergh’s 30th feature film, give or take, but it feels — and this is a compliment — like his first. It has energy, imagination and a sense of experimentation, as if Soderbergh were still fascinated by this thing called a camera. He shot “Unsane” on three iPhone 7s, and the resulting look is perfect for the film: jittery, prickly, a little raw, much like Sawyer herself. With nods to Samuel Fuller’s classic madhouse thriller “Shock Corridor” (1963) and a low-budget feel that gives the film an added sense of grit, “Unsane” qualifies as a minor masterpiece.