In Michel Faber’s satirical novel, from which the film was adapted by Mr. Glazer (“Sexy Beast,” “Birth”) and Walter Campbell, her character, unidentified in the film, is named Isserley. Dispatched to Earth, she picks up muscular men who are fattened and turned into high-end meat delicacies for domestic consumption on her home planet. The film dispenses with the novel’s back story and plot, the better to conjure a mood of nightmarish alienation. The story is so stripped down that at a certain point its lack of clarity will frustrate viewers wanting more information.

“Under the Skin” was filmed in tones of darkness. Ms. Johansson’s expressionless character is frequently seen in shadow, out of which she emerges like a film-noir vamp. The van was equipped with tiny surveillance cameras to capture her interactions with the victims, real-life hitchhikers unaware that they were being filmed. Ms. Johansson’s husky voice, with its cultivated London accent, is as seductive as her body, which she brazenly displays. Because the men have thick Scottish brogues that render much of what they say unintelligible, they seem as alien as she does, and you begin to see these earthlings through her eyes.

In an early scene on a beach, she observes the attempted rescue of a swimmer buffeted in heavy surf as a baby at the far end of the sand cries. When the rescuer emerges from the water and collapses, she approaches him and beats him to death with a rock as the baby continues to wail. She seems utterly indifferent. One hitchhiker has a disfigured face like that of the Elephant Man, but she seems not to notice and tells him he has beautiful hands.

Late in the movie, Ms. Johansson’s character appears to become more human and vulnerable after a sexual interlude with a man she picks up. A connection has been made. Her defenses lowered, she finds herself without her fur coat on a hiking trail in the highlands, menaced by a stranger. The movie’s eerie, climactic image challenges our conventional notions of human identity and leaves us reflecting on the possibility that every being in the universe is an alien in disguise.