Mr Cobb is in need of a private investigator. His younger brother, Peter is a gambler, and after being in a card game with Sir Arthur Ostrum, a gentleman with a large estate and a foul reputation, he won at the table, leaving Arthur in a considerable amount of debt. He intends to clear this debt, by allowing Peter to marry his youngest daughter Margaret. However, Margaret has two older sisters, and both of them lost their husbands at a very young age. Arthur then plundered their estates. Mr Cobb fears that he has the same fateful plans for his younger brother...