“Love was a gamble she couldn't afford to lose.”

Mary Rutledge arrives from the east, finds her fiancé dead, and goes to work at the roulette wheel of Luis Chamalis' Bella Donna, a rowdy gambling house in San Francisco in the 1850s. She falls in love with miner Jim Carmichael and takes his gold dust at the wheel. She goes after him, Chamalis goes after her with intent to harm Carmichael.