Miss Mirabelle Thompson, at almost one and twenty, is astonished to discover she is an heiress having believed herself to be a penniless orphan. Immediately she rents a house in Cavendish Square and commences her new life. She has no interest in finding a partner, and if she did wish to marry, it would be someone who loved her for herself and not her money.
Rordon, the Duke of Clonmel, is equally astonished to discover upon inheriting the title from his brother that the estate is forfeit, and all he has are debts. He only has one way out of this impasse and that is to seek a rich bride in London. Even an impoverished Irish duke will be considered a desirable husband for the daughter of a wealthy cit. Mirabelle and Rordon attend the same Christmas house party. This has been arranged by a Mr. Bradley with the intention of finding his daughter an aristocratic husband—preferably a duke. Those attending the event are either rich young ladies in search of a title or poor aristocrats in search of a rich wife. Can Mirabelle and Rordon overcome the obstacles between them and find happiness together?