Judge Avery's daughter Viola is arrested in a police raid on Chinatown's most notorious gambling casino. Facing public disgrace and her father's anger, Viola romances immigration officer Bob Baxter who provides an alibi for her. Baxter is drawn to Viola but also sees her as a source of information about the casino boss's white slavery ring. As Baxter's attention becomes clouded with infatuation, Viola must keep the inquisitive detective at bay. Owning a debt of silence to the casino's owner, King Moss, Viola finds herself ensnared in a dark web of Western intrigue and Oriental crime. Growing feelings for Baxter drive Viola into danger and she is kidnapped as a pawn in Moss's elaborate underworld scheme.