Sian Anderson, Meg Foster, is an American novelist who leaves Los Angeles to seek inspiration on the remote Greek island of Monemvasia. She rents a weathered house owned by Elias Appleby, Robert Morley, an eccentric elderly man who warns her that a strong, unrelenting wind will sweep the night and urges her to stay indoors while the storm from the sea rages outside. After Elias departs, she meets Phil, Wings Hauser, a gruff American handyman who also lives on the property and keeps to the shadows of the place.
That night, the wind howls through the cliffs as Phil murders Elias after a tense confrontation. From a distance, Sian spots Phil burying something, and a rush of fear drives her to investigate further. She discovers Elias’s corpse and, overwhelmed, dials her boyfriend back in Los Angeles, John, David McCallum, begging him to report what has happened since she isn’t sure how to reach the Greek rescuers. She also tries to reach Elias’s wife, Dina Giannakou, but their language barrier prevents communication. The sense of danger tightens as Sian realizes Phil knows she has seen too much.
Phil, realizing Sian can identify him, intrudes into the house through the basement. He attacks with a sickle, and in a desperate counter, Sian blocks him by sealing the basement hatch and dousing him with kerosene. The basement becomes a ominous game of nerves as Phil toys with the nearby generator, causing the lights to flicker and plunge the house into brief, eerie darkness. When Elias’s wife arrives, calling out for her husband, Phil murders her as well, adding a new layer of peril for Sian.
Back on the phone with John, she learns that two operators are attempting to reach Greek authorities, but the weather and the isolation complicate every effort. Kesner, Steve Railsback, an American marine captain stranded on the island by the storm, arrives and offers to help, briefly easing the tension as he assesses the danger. Yet Phil infiltrates the house again, and Kesner is found dead in an upstairs bedroom, alongside Elias and his wife, their bodies hidden away in a closet.
With the house now a trap, Sian recalls Elias’s warning that there are several locked closets meant for storing hunting weapons that must remain untouched. She locates the closets, finds a rifle, and becomes the hunter rather than the hunted. From a second-floor window, she opens fire on Phil, who stalks the grounds below. He climbs toward a balcony, and Sian sets up a booby trap by rigging a door shutter with a rope. As Phil closes in, she cuts the rope, the door slams outward, and he impales himself on his own sickle, crashing to the ground.
Assuming she is safe, Sian flees through the villa’s corridors into a nearby cavern revealed by a broken floor. She wanders through winding subterranean passages until dawn breaks, emerging onto a rocky coastal path. A honeymooning couple drives past on the road below, unaware of the peril that pursues her. For a moment, she calls out to them, hoping for help, but they do not hear her. The nightmare seems almost behind her—until Phil, who somehow survived the earlier fall, returns to chase her through the cliffside maze.
In a final, harrowing pursuit, a gust of wind helps seal Phil’s fate as he loses his footing on the jagged path and plummets to his death. The dawn light paints the island in a muted glow as Sian, exhausted and wary, staggers toward the rock face and inches her way toward freedom, her ordeal echoing in the wind that continues to roar along the shore.
