As the film opens, we see a portrait of a beautiful woman hanging on the wall. A man begins to talk of Laura's death and how he was the only one who really knew her; his name was Waldo Lydecker. He was just beginning to write her story when detectives began to see him. Laura was murdered in her apartment.

Waldo talks to one of the detectives and tells him that he will repeat the statement he made the day before. He had dinner with Laura who was then supposed to be going out of town. He ate alone and then got into the tub to read. Waldo reads this off a page, and the detective asks if he wrote it down so that he wouldn't forget it. Waldo replies that he is the most misquoted man in America. Finally, he discovers that the...