Many of the 20th century's most celebrated fictional sleuths appeared in Hollywood movie mystery series of the forties. This volume focuses on 19 series (146 films): The Saint, The Lone Wolf, Sherlock Holmes, The Shadow, Nick Carter, Michael Shayne, Ellery Queen, Boston Blackie, The Falcon, Mr. District Attorney, Wally Benton, Crime Doctor, The Whistler, Inner Sanctum, Dick Tracy, Philip Marlowe, Jack Packard and Doc Long, Steve Wilson and Lorelei Kilbourne and John J. Malone.

For each series, there is an overview of the source material, the individual films, and the performers who acted in them. An overall review of each film is included, with a critique of the film's quality and the cohesiveness of its plot. For movies based on written works, a comparison between the film and its literary original is offered.