Ellery's old college chum, Linville Hagen, is accused of murdering mobster Nick Danello, and Ellery must find a missing witness who can prove his innocence. This missing witness was a woman wearing a green dress - a description, of course, which could fit any woman in New York. Frank Flannigan comes along for the ride too, and this time he's not quite so antagonistic towards Ellery.

Ellery and the Inspector travel to Hollywood in order to watch the filming of an adaptation of one of Ellery's novels into a movie. At the studio, they meet the actors who will be portraying them.