"This arty sci-fi thriller, adapted from a novel by Michael Faber, raises far more questions than it answers, yet that enigmatic quality is central to its appeal. Under the Skin hints at several different readings without confirming any of them. That ensures that the film stays with you.
An alien life-form materializes on the outskirts of Edinburgh, occupying the body of a black-haired young woman (Scarlett Johansson). A man, possibly another alien in human form, provides her with a white van and sends her on her way. After spending time in the city, she proceeds to the remote forests of Scotland. She offers rides to a series of strange men, seduces them, and traps them in an undefined black space that mutates into an aqueous, apparently deadly substance. This pattern of travel, seduction, and predation continues until the alien meets a couple of riders whom she seems to regard with sympathy: a disfigured young man who claims to be a virgin and a rural loner who shelters her after she's stranded in the countryside. One wonders, though, whether her sympathy is genuine or just a more sophisticated lure.
Glazer reportedly spent ten years developing Under the Skin, and some aspects of it are so immaculately realized that they seem eerily inevitable. The audio design immerses the listener, its layered soundscapes suggesting how overwhelmed the alien might feel on earth. Glazer disorients the viewer through his use of the Steadicam, exploiting its uncannily smooth movement to suggest the perspective of a superhuman voyeur. The most impressive effects come during the seduction sequences, as Glazer creates the blank, ever-shifting environment of a nightmare.
And just as Kubrick did from 2001: A Space Odyssey onward, Glazer offsets the immaculacy of the effects with moments of spontaneity. The scenes of Johansson picking up strange men, for instance, were all unstaged; Glazer instructed the actress to offer rides to random men and shot these encounters with a hidden camera. Remarkably, these scenes fit right in with the rest of the movie. Like its protagonist, Under the Skin effectively draws us in while managing to stay beyond our grasp." - The Chicago Reader