Hell hath no fury like a woman with unlimited access to dingy lairs in Glasgow, Scotland.

That's one lesson to be gleaned from Jonathan Glazer's Under the Skin, a sci-fi/horror hybrid starring Scarlett Johansson as a gorgeous, man-eating alien who lures dudes home with the unspoken promise of sex—only to deliver an exceptionally elegant drowning. That leads to the second, more important lesson: If a beautiful woman in a white stalker van pulls up next to you on the street and asks if you're alone tonight, say no and run for the Highlands. (Not that the men in this film were warned: Much of the movie was shot with hidden cameras, with the guys just regular Joes.)

Though based on the novel by Michel Faber, Under the Skin is greatly stripped down. Why ScarJo, decked out in skintight, acid-washed jeans and a Karen Carpenter wig, is compelled to take men home to one her many mirror-floored apartments (she owns more property than John McCain) is never explained beyond a creepy, 2001: A Space Odyssey-esque montage of images that includes a bloody meat conveyor belt and an exploding star.

We do know there's a man on a motorcycle who's responsible for cleaning up the evidence of our antiheroine's dirty work. We discover that her victims, eager to get naked and lope after Johansson like a gang of horny Gungans, end up suspended in blue plastic, staring at their hard-ons. If they make physical contact with each other, they burst like balloons. But why?

The lack of clarity is part of the film's appeal. Under the Skin stubbornly refuses to explain itself, letting Johansson's voluptuous body do the talking. It's clearly concerned with the destructive power of physical beauty: The lone man allowed to escape (at least for a moment) has a face only a mother could love. After she lets him go, this predatory fembot stares into a mirror, as if somehow understanding that her comeliness is the root of all evil.

That said, the film is frustratingly shallow at times, and would be nothing without its soundtrack. Part otherworldly bee-buzzing, part feedback and all straight-up spook, Mica Levi's score sets a terrifying tone. Prepare to be scared shitless, even as you shake your head over the story's many twists, particularly its turn toward tenderness at the end. Is this black widow becoming human? Has she grown a heart under that skin…er, polymer? And, if so, what is a heart worth in this landscape of lust and loneliness?

Critic's Grade: B

SEE IT: Under the Skin is rated R. It opens Friday at Fox Tower.