New York gangster Ben 'Bugsy' Siegel takes a brief business trip to Los Angeles. A sharp-dressing womanizer with a foul temper, Siegel doesn't hesitate to kill or maim anyone crossing him. In L.A. the life, the movies, and most of all strong-willed Virginia Hill detain him while his family wait back home. Then a trip to a run-down gambling joint at a spot in the desert known as Las Vegas gives him his big idea.