The dramatic disappearance of the wife of a wealthy businessman from a small hotel on the French Riviera prompts a distinguished English widow to recount her fleeting encounter with a young gambler many years before. Crushed by the loss of her husband, she wanders aimlessly around Europe, finally drifting to Monte Carlo. One evening in the Casino, she is mesmerised by the obsessive gambling of a young Polish aristocrat. Impulsively following the broken man as he stumbles from the roulette table, she embarks on twenty-four hours of passion, redemption and betrayal which will haunt her life forever.