While her husband is away, Penny is visited by an intruder, who bursts through the door and demands to see her husband Harry. When Harry is nowhere to be seen, he attacks and tries to rape her. Picking up a nearby shotgun, she shoots him in the face.
When Harry returns, Penny explains what has happened. They follow a trail of blood into the woods. Harry finds the body, turns it over and immediately recognises it as Charles Willoughby, an old business associate.
Harry explains to Penny that they must bury the body and clean up the blood stains in the house because they have no licence for the shotgun. He also suggests that if Penny confesses, she may have to go back to the mental hospital.
While Harry buries the body and pushes Charles's Land Rover in the lake, Penny burns the blood spattered bedclothes.
As they sleep that night, Penny wakes up and looks outside to see Charles's Land Rover parked outside. She turns round to see, for a moment, Charles's blooded face.
The next day a policeman comes round and asks questions about a missing Charles Willoughby. Harry admits of knowing him but simply explains that he has seen no sight of him.
Harry explains to Penny that they must act normally. That night they got to a party at Margaret's, and at the party penny sees a vision of Charles. Penny becomes hysterical, and Harry has to carry her away
While browsing through an antique shop, Penny sees yet another vision of Charles. This time Harry loses patience, and when they arrive home, he digs up Charles body and shows it to Penny, proving that he is still dead.
Still shaken, Penny goes back to see Margaret, who happens to be a psychic. During a seance, she manages to get through to Charles. Penny hears Charles voice saying, "I must be revenged." Margaret collapses. When she comes round, she states that the spirit is too strong for her, and the only man who may be able to help is the Swami Gupta Krishna...
In her fragile mental state, Penny reluctantly agrees to a seance with the Swami for a fee of 150,000 pounds.
The seance is set up. The Swami, in the presence of Margaret, Harry and Penny attempts to contact the restless spirit of Charles Willoughby. The Swami succeeds and the blood spattered face of Charles appears in the room. His spirit is unable to be soothed and his voice booms out, "I will be revenged." This is too much for Penny to take, and in her anxious state, she flees from the room.
Penny shoots herself dead in the bedroom. An ambulance is summoned which takes her body away.
In the living room, four people congratulate themselves. It has all been a set-up. Penny was meant to be sent insane, so that they could share her money. Charles Willoughby was never shot, and the Swami ( who is in fact the man who played the policeman earlier ) is a fake. Charles, Margaret, Harry and Richard ( the fake Swami ) toast their monetary gain with champagne. As they do, the patio doors are flung open and Penny's spirit appears. The pile of money on the table bursts into flames as Penny roars, "I will be revenged."