In the opening shot, there is a tiny ball of light, which turns into a bright circular flash, slowly coming into view with a circular object. Amidst the ominous tone that plays, we hear a woman's voice making sounds, trying to get her speech down to being perfect.
We see what appears to be a black liquid circular pool. The light and the circular object come together to form an eye - a mysterious woman's eye. A shot of a long curving road between the mountains of Scotland with a single headlight appears.
The view changes and we see it is an unknown man on a motorcycle. The man rides his motorcycle to a tunnel where he stops. He gets off the bike and walks off the road into a ditch, appearing a moment later carrying a young woman's body.
He throws the body into the back of a white van. Next, we see the woman's dead body being unceremoniously undressed by another naked young woman in a white, brightly lit room. After the woman is dressed, she stands over the body and stares at it.
The camera focuses on the now nude woman's body and we see a tear fall from her eye - we are not sure at this point if she was indeed dead, and the tear was simply a reflex, or if she is perhaps in some catatonic state.
The identity of this woman remains unknown throughout the film, but due to the tear falling, and due to the motorcycle man knowing exactly where the body was, she may have been in some sort of comatose state and aware of what was going on. The woman who took the clothing bends down over the body and seems to inspect something she picked up from the body. It appears to be an ant that was crawling on the dead/comatose woman's body.
The next scene opens with a cloudy sky and mysterious lights above a tall skyscraper. This scene is supposed to be the indication that it is an alien presence that the film is depicting, although this particular scene is brief. The mysterious female is then seen leaving a dirty rundown looking house. The white van is parked outside, and the motorcycle man is there as well. The relationship between the two is unclear at this point, although they seem connected.
These two, although seen together in a few scenes, and often in the same areas, do not communicate at all in the film, leaving us to assume they communicate telepathically or some other way. The man departs on his motorcycle, and the woman gets into the white van and begins to drive. Later, the mysterious young woman/alien is seen in a crowded shopping mall. She seems to pick out several items of clothing including a faux fur coat and red lipstick.
She then continues to drive in the white van, eyeing men as she drives past. She passes through several crowds of people before stopping on a less crowded street to approach a man who is alone, like any good predator would. She asks him for directions and they converse. Several separate scenes repeat the same pattern- she seeks out lone men walking and asks for directions or some other banal topic.
She asks basic questions of these men, such as their names, where they are from, and also more in depth questions that lead you to think her intentions might be more sinister. She asks questions such as if they are alone, if they have a family, if they are going anywhere, and also more personal questions, studying her prey, such as, "Why do you like to be alone?" She drives off when a subject appears to not fit her criteria- at one point, a siren from a police car sounds nearby, and she drives away.
At another point, one of the men she is speaking to is called to from somewhere in the distance. She loses interest and drives off. When she is able to determine a candidate is adequate, she invites him into her van for a ride and begins another line of questions- "Do you have a girlfriend? Do you think I'm pretty?" Finally, she finds a man with a green and white scarf who fits her criteria, and we see them entering the run-down house.
The surroundings fade to black, and as she looks at the man seductively over her shoulder, undressing, he follows, also undressing. Once the man is completely naked, as he approaches her, instead of getting closer, he suddenly sinks into the floor, as if it were made of liquid. The man appears not to notice, seeming to be hypnotized by the woman.
Once he has fully disappeared, the mysterious alien/woman picks up her clothing and walks off camera. Some time passes, and we can assume the alien woman continues her preying on men, due to scenes of her in the van again driving around.
The alien woman is at the beach, and we see her watching a solo male swimming in a wetsuit. When he comes to shore she begins her line of questions, what is he doing here, why is he in Scotland. The two are interrupted by the screams of a woman being pushed out to sea by huge waves, and a man in a heavy coat seems to be swimming after her.
The man in the wetsuit rushes over to help, while the alien woman stands there watching, completely passive, as these events progress. The woman in the water is eventually lost to sight, but the man in the wetsuit manages to pull the man in the heavy coat to shore, only to have the man rush back into the waters chasing after his wife, who has already been swept too far out. The man in the wetsuit, exhausted from his efforts, does not chase him, instead collapsing on the shore. We seem him move so we know he is alive.
Finally, the alien woman springs into action, at first we think to help, but what she does instead is find a rock and bash the man in the wetsuit in the head, to ensure he is either unconscious or dead. The scene cuts to another part of the breach where she is dragging the body of the man in a wetsuit past a crying child. Since the man in the wetsuit was alone, we can assume the baby belonged to the man and the woman who were swept to sea. The alien woman is completely unphased by the crying child, intent on her task of dragging the body.
She eventually gets the body in the car, and we see the man on the motorcycle locate a tent on the beach which we can assume belonged to the man in the wetsuit. He appears to fold up the tent, and take it with him. We are reminded of the opening scene in which he had originally found a woman either dead or comatose, so we can assume either he or another alien made a victim of that woman, and he was sent to clean it up like he is doing now. We hear the child still crying, and it is now night.
The motorcycle man walks toward the child as if to console him, but stops and bends to pick up an article of clothing that was left behind, as if the wetsuit man's body and taking all of his personal belongings are of a significant importance, but the crying child is not. We also see the woman, back in the van, and hear crying again, she seems to notice the crying this time. But she looks out her window to see she is back in the city, and the crying is from the vehicle next to her, where a child is in the back seat of a vehicle parked nearby.
It is not the same child from the beach, but perhaps she was thinking about that child after all. In the car on the other side of her is a group of rowdy men who seem to catcall her. She follows them around what seems like an abandoned building, and when she sees the man who called to her alone outside, she exits the van and starts to approach. As she nears the other side of the building, she suddenly sees a large crowd and realizes the man had gone into a club.
A crowd of women intercept her as she turns to leave and insist she go into the club with them. The alien looks absolutely baffled by these woman and gets ushered into the club with the throng of women urging her to do so. As soon as she enters the club there is loud music, flashing lights, and people everywhere.
The first door that she sees, the alien woman escapes into, but it is not a door that leads outside, instead it leads to some sort odd lounge area, where she is again approached by the man who called to her from the road. He insists that she let him buy her a drink, and we see them dancing in the club.