The two Scarlett Johansson films currently in theaters—Captain America: The Winter Soldier and the avant-garde Under the Skin—would make a thought-provoking double feature. The former has been praised for finally bringing a strong, independent woman into the comic book movie fold, but Johansson’s secret agent is still an object of the male gaze; in an early scene, she dispatches a bad guy with brute force, then the camera lingers at ass-level as she walks away. Under the Skin is about this objectification. Both a naturalistic work of science fiction and a feminist masterpiece, this uncompromising and often brilliant work of cinema is occasionally hard to figure out but impossible to ignore.

Johansson plays an alien who comes to our planet on a mission to lure men to their death. After assuming the form of a desirable female human, she prowls the streets of Scotland in a cargo van, seducing young men with nothing more than a smile and a promise of sex, then brings them back to her house, where they willingly submerge themselves in a pool of mysterious black liquid.

Little else is explained; unlike in the Michael Faber book on which the film is based, we never learn what motivates the alien, and Johansson’s performance gives nothing away. She may act the part of a desirous, young woman, but there is nothing behind her alluring eyes. For an actress with Johansson’s charisma to appear so emotionally vacant—while baring so much of herself physically—is an immense achievement.

But it also leads to the film’s greater purpose: By eschewing the specific motives of the lead character laid out in the novel, director Jonathan Glazer (Sexy Beast, Birth) casts the entire film as a discourse on how our society looks at women. Johansson’s alien is something of a blank slate, and her mission in life—to sexually attract young men—is the same one our society tries to ascribe to all women. She even uses the same tools. She buys a fur coat and skin-tight jeans at the mall and hangs around a dance club, waiting to be propositioned. Through the eyes of this foreigner trying to fit in, Under the Skin becomes a damning anthropological study of gender relations in the 21st century.

Still, ideas without artistry become an intellectual exercise, and Glazer never allows his film to fall into that trap. He effortlessly mixes a thrilling cinéma véritéstyle—many of Johansson’s interactions on the street were filmed with hidden cameras and non-actors—with some of the most striking images in a sci-fi movie since 2001: A Space Odyssey. When you finally see what’s under this alien’s skin, it is one of the year’s most haunting scenes, but what matters is that the film digs deep enough to show it.