In the arena of a vast New York sports palace, a man lay dead, murdered during the opening scene of a spectacular rodeo.
Can you, as Ellery Queen does, follow these clues to the murderer? - A dead man's belt. What was the meaning of the deep ridges in the leather?
An ivory handled revolver. - How could the "feel" of the gun-butt provide a clue? The broken locks on a green box.
Did the way the locks had been bent point the way to murder?  These are the big points in one of the toughest mysteries ever tackled by Ellery Queen. It was a murder witnessed by 20,000 people, but only Ellery solved it. Do you think you can, too? 

This mystery is about...

• A $5000 horse
• Glass balls shot in mid-air
• A horrible scar
• A thirsty horse that would not drink
• A $3000 check
• Ivory inlays on an old six-shooter
• A search of 20,000 suspects
• A small bank balance
• A newsreel scoop of a murder
• A $42,000 gambling debt
• The 41st cowboy who wasn't a cowboy

The American Gun Mystery (1933) is the sixth Ellery Queen novel, and one of the author’s most ambitious experiments in transplanting the Golden Age detective story into an American setting both vast and theatrical. The novel opens in the New York Colosseum, a sports arena filled with 20,000 spectators, all gathered to watch Tony Mars’s spectacular rodeo. Among them sit Inspector Queen, Ellery, and Djuna, alongside Hollywood actress Mara Gay and Kit Home, the adopted daughter of Buck Horne, a legendary cowboy shooter attempting a comeback. During the climactic event, Horne rides into the arena followed by forty other riders—but there are forty-one instead of forty. At the height of the synchronized gunfire, Buck suddenly falls dead, shot through the heart before the eyes of the immense crowd. The impossible crime is immediately framed: forty-one cowboys, twenty thousand witnesses, and yet no one can identify the killer.

Ellery Queen’s narrative is structured as both puzzle and spectacle. Clues abound: the ridges in a dead man’s belt, the ivory-handled revolver whose “feel” plays a crucial role, the bent locks on a mysterious green box, and the vanishing gun itself—a central device handled with ingenuity (Michael E.Grost). The investigation spans not only the rodeo but the interwoven world of show business, gambling debts, Hollywood connections, and a newsreel scoop of the murder. The mystery becomes more complex when, at the very spot where Buck Horne died, another rider is later shot with the same revolver during a reenactment of the event (Margaret Germond).

The book was received with both praise and criticism. Some reviewers admired its scope and ingenuity: the New York Times called it “a humdinger,” while Lionel Houser of the Indianapolis Times predicted and confirmed its bestseller status. Dorothy L. Sayers, writing in 1933 under the subtitle “An American Nut Worth Cracking,” criticized Queen’s overwrought style—“Mr. Ellery Queen is determined to be literary or die”—yet conceded that it was “a rattling good yarn with a well-constructed mystery”  (Joe R. Christopher). Similarly, Scribner’s Magazine admitted the book was “somewhat over-written” but praised its intricate plotting.

Above: Ads from four consecutive New York Times Book reviews in 1933 indicate that Ellery Queen's The American Gun Mystery was being reprinted every week in its first month of publication.