This account contains some plot details, although I've tried to portray those details, and their import, as obliquely as possible. I wouldn't call them "spoilers" but you never can tell these days. Be warned.
Critics have been calling Jonathan Glazer's Under The Skin "mysterious," "mesmerizing," "elusive," and "hypnotic," and it is arguably all of those things. It is also at times terrifying, at other times deliberately ennervating (I think), and finally harrowing. One of the things that makes it possibly a masterpiece is the way it acheives all of the above qualities. In many respects Under The Skin is an entirely conventional film. It represents a rudimentary and perhaps even exemplary cinematic narrative by presenting the viewer with a series of events, depicted in the order in which they wuld have occured had they happened in "real life."
This is true, I think, even of the opening shots, a montage that recalls imagery from the Jupiter voyage sequences in Kubrick's 2001: A Space Odyssey. The action depicted looks rather like one would imagine a spaceship docking, or a futuristic piece of machinery performing some sort of task of alignment. Because of that, it's rather a shock when the montage concludes with a closeup of what seems to be the iris and pupil and white matter of a human eyeball. Only the white matter is almost too white. This image, too, recalls the Kubrick film but it also suggests that what we've been watching leading up to it has been depicted at some kind of macro level. But once that human eye is recognizable, the viewer might feel more subsequently grounded. And indeed, things start happening in a world that we can recognize as more or less our own, or, as Scotland, which is where the movie is set and was shot. A man on a motorcycle driving at night pulls off the the side of the road next to a white van. He parks the bike, goes down a flight of stairs off the roadside, and emerges soon after carrying what appears to be a human corpse. So far, so comprehensible. The action then shifts to what appears to be the interior of a room-sized box encased in white light. A nude woman in silhouette removes the clothes from the corpse and puts them on herself. This is weird, all right, but there's nothing in the film's grammar to indicate that this sequence is taking place out of temporal or spatial continuity with the previous scene. Once we see Scarlett Johansson driving the white van from the roadside scene shortly after this, we are all "agreed," via our understanding of film grammar, that some sort of transformation has been accomplished.
The movie's perspective is confined to that of the creatures, whatever they are, portrayed by Johansson and the fellow on the motorcycle, and the other identically-dressed fellows on motorcycles who turn up at what is ostensibly the movie's climax. There is no outside, human figure to provide exposition. There's no government agency tracking the activities of Johansson's character. Her activities, as you've likely already read, involve driving her van slowly through the streets of Glasgow, speaking to various anorak-clad young men, and depending on their walking destinations and/or marital status and such, luring them back to her "place." The place, such as it is, seems an endless black corridor with a reflective glass floor. Here's where the movie's narrative strategy, its ellipses and/or elisions, its choice concerning what kind of information it's going to provide, either benefits its mission or, as you've seen in some negative reviews, maddens/addles the viewer. (Although maddening/addling the viewer may well be its mission in a sense.) Once inside, none of the fellows ever observe, "This is a weird apartment" or any such thing. They merely follow the character played by Johansson as she strips of her clothes, and strip down themselves, even as they sink into the floor. Now don't get me wrong. Ms. Johansson is a very attractive woman, but even were she intent on seducing me—not a likely scenario, admittedly—I would likely make some comment were she to bring me to such a locale. I'd at least want to hit the bathroom to see if I had anything in my teeth. So what's with these guys? Are they that thick? Are they literally hypnotized? Are they seeing somethng else? We do not know.
Nor do we know, later on, exactly why one of her potential victims does not sink. Although we are certainly invited to guess. What's finally most terrifying about the film is the matter-of-fact way it treats bizarre, horrific actions, and the sometimes chilling, sometimes poignant blankness of its lead character—it simply won't do to call her a "heroine" or even to call her a "her"—with such utter matter-of-factness. It is very much a movie with a beginning, a middle, and a shuddering end.