Amanda Hopper goes to bed listening to an audiotape of her widower father, Elliot Hopper, telling a ghost story, because Elliot himself is still at work at Collins, Ltd. Ending the story, Elliot’s voice tells Amanda that on Thursday he will get his promotion and qualify for the company’s insurance and pension plans, and then he can spend more time with her. The following morning, as Elliot prepares to return to the office, he hears Amanda and his other two children, Diane and Danny, mention that today is Diane’s seventeenth birthday. Realizing he forgot to buy a gift, Elliot tells Diane that after Collins assigns him a company car on Thursday, she can drive the family station wagon. Elliot recalls that on his ninth birthday, his father dressed in a bunny costume and wore it for a week because the zipper broke. As Diane prepares to drive him to work, Elliot reminds Joan, the attractive lady next door, that they have a date for his company banquet on Wednesday night. Downtown, as Elliot rides the elevator to his office, a Collins executive, Mr. Seymour, congratulates him for being entrusted to handle the big merger on Thursday. The last to leave the elevator, Elliot steps off seconds before the cable breaks and sends the car smashing into the basement. Later, hurrying to a meeting at the Union Bank, Elliot flags down a taxicab driven by Curtis Burch, a crazed Satan worshipper. Curtis zigzags through traffic at high speed and smashes through the side of a bridge, dropping himself and Elliot into the river. Elliot escapes, but when he climbs out of the water and returns to the bridge, a policeman cannot see him and a bus drives through him. Elliot walks home, passes through the closed front door, and falls halfway through the floor. The kids can see but cannot hear him. When one of them turns on the lights, Elliot disappears. Danny, a budding magician, congratulates his father on doing an excellent trick. Diane turns the lights back off, and Elliot reappears. Playing charades, he informs them that he is a ghost. Suddenly, Elliot floats through the ceiling, flies into the sky, and lands on the desk of Sir Edith Moser in London, England. Sir Edith, who pronounces his name “Eddith,” tells Elliot he summoned him because there was a disturbance in the “spirit ether” on Elliot’s way to the “hereafter.” Elliot demands to return home until Thursday, in order to provide for his children, because he cashed in his life insurance policy and mortgaged the house to pay for his late wife’s medical bills. Sir Edith doubts Elliot is able to make it beyond Wednesday, but agrees to send him back, after first synchronizing Elliot’s lips with the sound of his voice. When Elliot arrives home, he is able to talk to his children. His boss, Emery Collins, telephones, demanding to know why Elliot missed the important negotiations meeting at the bank. Elliot assures Collins he will be in the office tomorrow. The next morning, Diane drives Elliot, Danny, and Amanda to his office. The kids draw the curtains and turn the lights low so that Elliot is visible, then leave. Elliot’s secretary, Carol, informs him that he is scheduled that day to take his life insurance physical, which is required before Thursday. Elliot telephones Diane and tells her to bring him a hat, overcoat, scarf, sunglasses, and tape cassette player. Wrapping the scarf around his head and wearing the other clothing, he is visible as he goes to the doctor’s office. A nurse sends him to a room where he has to disrobe, so Elliot turns down the lights to make himself visible. When a doctor listens to his heart, Elliot holds the cassette player behind his back, playing a recording of a heartbeat. Sent to the X-ray room, he holds a medical skeleton in front of the machine as the nurse steps into the next room to take his X-ray. He steals a urine specimen from another patient. Later, as Diane drives her father home, she stops when she sees her boyfriend, Tony Ricker. He invites himself into the passenger seat, forcing the invisible Elliot to squeeze into the middle, but when Tony makes a sexual advance toward Diane, Elliot shoves him out of the car. At home, a nosy neighbor boy named Stuart observes strange things happening at the Hopper house. When Joan drops by to see Elliot, he sends Amanda to tell her he is not available. Elliot’s son, Danny, asks him to help with the “trunk of doom,” a magician’s act he is set to perform for school career day. Suddenly, Mr. Collins and other executives arrive at Elliot’s door, demanding to continue the negotiations. While Danny takes the men into a darkened room, Elliot hurries next door in his “invisible man” costume to apologize to Joan, then runs back home to conduct business. Across the street, the neighbor boy, Stuart, observes the strange figure through binoculars and telephones Elliot during the executive negotiations. He threatens to go to the newspapers with the news that Elliot is a space alien if he does not give him $50,000. Elliot briefly excuses himself and floats across the street to accost Stuart and show his true ghost-like state, which causes Stuart to faint. By the time Elliot returns to the house, the executives have gone. The telephone rings, Elliot answers, and Tony Ricker asks for Dianne in a disrespectful manner. Elliot spirits himself through the telephone line, partly emerges from Tony’s telephone as an astral figure, and orders the terrified teenager to never call Diane again. On Wednesday, the following day, Danny goes to school with his “trunk of doom,” worried the trick will not work. Diane is happy to see Tony at school, but he runs from her in terror. Elliot goes to work, darkens his office, and begins a slide show presentation for the other executives. Meanwhile, Danny’s classmates lock him in chains. He climbs into the trunk, and students close it shut. When Danny drops a hidden key out of his mouth, however, he is stuck. Diane telephones her father that Danny has gotten in trouble. Elliot leaves the business meeting and floats to the school. Invisible in the lighted classroom, he picks up the trunk and sets it on the teacher’s desk. Reaching inside, he retrieves the key so Danny can unlock his chains, then opens the lid and lifts Danny up like a levitating yogi. The teacher and students are awed by the trick. Hurrying back to the office, Elliot encounters his boss, Mr. Collins, who fires him. Elliot goes home to tell the kids he no longer has a job. His image begins to flicker. Joan from next door arrives fully dressed in evening attire and reminds Elliot he invited her to the banquet. Unable to continue the ruse, Elliot confesses he is a ghost and proves it by turning on a light. Joan screams. Suddenly, Sir Edith Moser arrives to inform Elliot that he is not really a ghost because he is not dead. He is a spirit whose body is still alive somewhere, but he must find it quickly. Sir Edith remembers only one other such case in America: a man who wore a bunny suit for several days until he was able to return to his body. Elliot exclaims that the “bunny suit” man was his own father. Sir Edit surmises that the phenomenon must be hereditary, which prompts the children to wonder if the same might happen to them. Elliot cannot remember just where he escaped from the river, so they contact police and hospitals. When Diane falls downstairs and is knocked unconscious, Elliot telephones for an ambulance. At the hospital emergency room, as Diane lies on a table surrounded by doctors and nurses, her spirit rises and floats into the next room. Elliot demands she return to her body, but Diane claims she is having too much fun. Floating through other rooms, she sees her father lying unconscious in the intensive care unit, but the chart on his bed has the name of the cab driver, “Curtis Burch.” She brings Elliot into the room, and promises she will return to her body if he returns to his. Elliot’s spirit lies down in his body. His eyes open as he revives from a coma. Diane revives in the ER as her spirit returns. Both father and daughter race into the corridor, and the other two children join them in a family embrace. They hurry outside, where a taxi driver pulls up and a frightened woman gets out. Looking into the cab, Elliot sees Curtis Burch. The madman announces, “I am yours to command, Evil Master.”