Clyde Umney is your typical 1983 private detective in L.A. After a round of poke and tickle with his secretary, he stops one jilted client from going through with a fake suicide attempt. He wards off a hitman in an elevator. And he takes out a posse of gunmen in a desperate diner shootout while giving hope to a young woman whose sister Umney rescued from prostitution.
At night Umney returns to his beautiful home and watches his neighbors, George and Georgia Demmick, dance the night away.
The next morning all is quiet at the Demmicks. Clyde is puzzled by the sudden silence but goes to work. When he arrives he finds the elevator operator, previously a nice guy, has become cynical and hardened with the discovery that he has cancer. The operator warns that the building owner, Sam Landry, is making some changes. Umney insists that this "isn't right" and the operator should always be there. The man just laughs.
When Umney arrives at his office he finds that his secretary has left him, claiming he's a sexist pig. Umney doesn't understand that either, but he is interrupted when the owner, Sam Landry, appears without warning in his office.
Umney is puzzled by Landry's unusual clothing and the mysterious Japanese briefcase he has. Landry opens it and says it's a word processor – "a typewriter with a brain" – and begins to explain that Clyde is... his fictional creation. Umney is a fictional detective in an unspecified period in the late 1930s that Landry created years ago and has steadily grown in readership.
Umney doesn't believe him and storms out. He goes back to the Demmicks and discovers that George killed his wife and dog, then committed suicide. Landry appears again and when Clyde confronts him, Landry renders him helpless with a few typed words. Landry then rewrites them back to Umney's office and explains that in the real world, his son drowned in an accident and he and his wife Linda have grown distant since then. Now Landry plans to take over Clyde's life, and when Clyde taunts him for taking the coward's way out, Landry writes in one of Umney's clients and has her kill herself. Once he's taken his petty revenge, he rewrites the story to his satisfaction.
Clyde appears in the real world in the Landry pool. He staggers in to the house to find a puzzled Linda, who quickly recognizes him as the fictional detective she helped to create. Desperate after years of separation, she comes on to Clyde but after she leaves, the pool girl arrives and Clyde flirts with her as well. Linda returns, finds them at it, and storms off to commit suicide. Landry, trying to adapt to his role of detective, senses her death even in his fictional world.
A disgusted Clyde vows that he will get his life back and get revenge on Landry. Slowly but steadily he starts writing as he tries to create a portal back to his own world...