Sebastian Carlisle, Duke of Trent, has inherited more than a dukedom—he's been saddled with the responsibility of ensuring his family's legacy. Determined to find a proper wife to be his duchess, he's planned for dowries and settlements, eventually an heir. But he certainly never planned on finding a beautiful, masked woman draped across his bed, begging to be seduced and very nearly succeeding until he discovers that his seductress is none other than Miranda Hodgkins, the flighty, free-spirited neighbor who has mistakenly sneaked into the wrong bedroom.
Madly in love with Robert Carlisle since he shared her first kiss, Miranda has planned a seduction designed to make him fall in love with her, only for it to all go horribly wrong when the man behind the mask reveals himself to be not Robert but Sebastian. The two strike an agreement—Sebastian will help her with Robert, and Miranda promises not to do anything to embarrass the duke or his family when his mother sponsors her season. But once in London, Sebastian is distracted from his quest for a proper wife by Miranda's wholly improper antics, and he soon finds himself sabotaging her attempts to catch his brother in order to keep her for himself.