Plot
In a small English village, a man driving a car encounters a black cat in the back seat. Through its stare, the cat causes the man to crash and die. The cat returns to its home, an old house occupied by Robert Miles, a former college professor of the supernatural who is reputed to be a medium. Living alone with the cat, Miles regularly records audiotapes at the tombs of the recently deceased. Meanwhile, American tourist Jill Trevers ventures into an open crypt to take photographs for her scrapbook and discovers a microphone on the floor. Venturing out, she meets police constable Sergeant Wilson who tells her not to visit the crypt again.
At a boathouse, teenager Maureen Grayson and her boyfriend, Stan, lock themselves in an airtight room to have sex. Stan eventually discovers that the room's key has disappeared. They are trapped as the room's air begins to run out.
The following day, Lillian Grayson calls the police to report her daughter's disappearance, and Wilson calls Inspector Gorley from Scotland Yard. Gorley rides into town on his motorcycle and gets a speeding ticket from Wilson at the police station. Meanwhile, Jill's search for the owner of the microphone leads to Miles, who discusses with her the barriers of perception and how to escape them. The cat leaps and scratches Miles, preventing him from hypnotizing Jill, who leaves in a hurry.
That night, a man named Ferguson leaves a pub and walks home. The cat appears and scares him into a disused barn. When the feline appears before him, Ferguson tries to escape along a beam high off the ground. The cat scratches his hands. Failing to keep his balance, Ferguson falls off to his death, landing on spikes on the ground.
The next morning, Gorley asks Jill to help photograph the corpse. She complies, seeing cat scratches on Ferguson's hands, which remind her of those suffered by Miles.
At Miles' house, Lillian begs him to help her find Maureen. Miles, who was romantically involved with Lillian years ago, reluctantly complies. Holding a bracelet owned by Maureen, Miles enters a trance and describes the boathouse, and the location of the missing key. The police and Lillian eventually find all as Miles had said. Using the key to unlock the door, which had been locked from the inside, they discover the bodies of Maureen and Stan. The key was outside the room, an impossible feat for a murderer since the only other way out was an air conditioning vent too small for a human. That night, Lillian dies in a fire started by the cat in her house.
Jill goes to Miles' house the following day and shows him photographs of the scratches on Ferguson's hands. Jill now believes that Miles exerts a supernatural influence over the cat. Miles says that it is the other way around.
That night, Miles drugs the cat and takes it outdoors, hanging from a tree branch. Supernatural forces are unleashed by its death, which also hit Jill as she sleeps at the village inn. The cat appears before Miles again. Gorley visits Jill's room to discuss with her the flashes of light and occurrences that happened an hour earlier. While leaving, Gorley sees the creature, getting attacked and hypnotized by it. He staggers on the road in front of a moving car and gets run over.
The next day, Jill, still thinking that Miles is the real killer, sneaks into his house when he goes out and snoops around his office, uncovering the recordings of his conversations with the dead. When Miles returns, she runs to hide in the cellar and encounters the cat, which appears and disappears before her eyes. Running away in terror, she is cornered by Miles. He says that the cat has picked up on his suppressed hatred for the townsfolk and is acting it out without his knowledge or control. Jill runs, but is attacked by bats in the cellar. Miles then knocks her out with a stick.
Jill wakes up bound and gagged while Miles walls her up alive in a space in the cellar. He has also taken her keys and emptied her hotel room, making it seem that she has left the village. However, Gorley, having survived the car accident, goes with Wilson and his superior, Inspector Flynn, over to Miles' house and insists on searching it for signs of the cat and Jill. Finding nothing, they are about to leave when they hear a cry from the cat. At the cellar, they notice the newly bricked-up wall and batter it down, finding a barely alive Jill and the dead cat, which was accidentally incarcerated there by Miles.
