The Jazz Age was an amazing time for “The Dream Factory” — especially to those who liked studio tyrants, union thugs, gangsters and Prohibition. The Volstead Act attempted to close the spigot on legal spirits. But you could always nip a swig on the streets from a seller with a flask strapped to his boot-top. It was the start of a new criminal profession — “bootlegger” — and it quickly stretched from the derelict warehouses of the East to the barnacled piers under the docks of San Pedro.

Mr. Volstead and his pals in Congress were only kidding themselves if they thought their high-minded “act” would change the way business was being done in Hollywood.

“The Ben-Hur Murders” shows how Prohibition opened the back gate to a new kind of criminal activity. Studio executives, agents and vulnerable film stars were suddenly dealing with a dangerous breed of black-market corruption.

In October of 1925, the top tier of L.A.’s ruling elite settled back in their V.I.P. stalls to witness the filming of the “Ben-Hur” chariot race. Irving Thalberg, Ramõn Novarro, Norma Shearer, Harold Lloyd, Douglas Fairbanks and hundreds more could only imagine what was taking place behind the scenes. Most of them would have found it every bit as shocking as the action down on the racetrack.

Here for the first time is the full story that has been covered up and soft-pedaled from the start by a fawning L.A. press. In “The Ben-Hur Murders,” the day, its dreams, and the scandals finally take their rightful position in the pantheon of Hollywood lore.