Rosalie Dean, an American vacationing in Monte Carlo, finds herself strongly attracted to a gambler named Maxfield Grey. Seeing that he has lost everything at the roulette wheel, she prevents him from committing suicide and forces him to accept a loan. With Rosalie's money, Maxfield more than recoups his losses, and the two are basking in luck and love when he suddenly is arrested for the murder of his ex-wife. Although Maxfield refuses to defend himself, Rosalie believes him to be innocent and, hoping to discover the truth, inquires into what appears to be an illicit romance between Maxfield's sister-in-law and a philanderer named Wally Gage. Rosalie learns that Wally, planning to steal away with Maxfield's sister-in-law, shot the deceased woman while struggling with Maxfield. After Wally is taken into custody, Maxfield is released and reunited with his faithful Rosalie.