Ghost is a love story with a supernatural theme. Sam and Molly are a young couple who move into an apartment in New York City. As the couple are returning home one night, they encounter a mugger who is carrying a gun. As a struggle ensues with Sam, he is shot and killed. At the moment of his death, Sam's spirit rises out of his body and takes its place beside Molly. Sam tries to comfort her, but Molly is not able to see or hear him. In the days that follow his death, Sam spends his time in their apartment learning how to navigate through objects. On one occasion, he sees the guy who shot him enter their apartment and search through their things.
Sam decides to investigate what is going on by following the man after he leaves the apartment. Meanwhile, Molly meets another tenant in the building who claims to be psychic. When Sam follows Molly the psychic named Oda Mae is stunned that she can really hear him. Until that time, she had always pretended to have psychic abilities. Over the next few weeks, Sam learns more about the mysterious man who shot him and the reasons behind it. Before Sam's death, he had stumbled onto some disturbing information at work. Some of the company bank accounts contained more money then they were supposed to. When Sam learned of this, he confided in someone he considered to be a friend.
As the story unfolds it turns out the person Sam decided to confide in was actually involved in the money matter. As a spirit, Sam cannot take charge of the situation and get justice for his murder so he enlists the help of Oda Mae. Following the plan Sam gives her, Oda Mae leaves clues about the murder and the money laundering. When justice is served Molly finally hears Sam say his final goodbye before he ascends into the light.