On a foggy night in 1850, Mary Rutledge and retired Colonel Marcus Aurelius Cobb arrive in San Francisco Bay aboard the clipper Flying Cloud. She had come to wed a wealthy owner of a gold mine, but he has lost his mine at the roulette wheel when the ball landed on red 13 times at the Bella Donna. The men at the wharf reluctantly inform her that her fiancé is dead, murdered most likely by Louis Chamalis, the powerful owner of the Bella Donna restaurant and gambling house.