Nicholas Villines is the heir assumptive to a viscount. His father left him in dire straits, but he's managed to recover the family fortunes and re-enter society. His childhood friend Elizabeth is now in London, hoping to make a modest marriage, as she is a woman of very modest means. Not so her beautiful (and rich) cousin Amelia. Every agrees that Nicolas and Amelia would be a perfect match. As Elizabeth and Nicholas rekindle their friendship, society can talk of little but The Mayfair Thief, a mysterious and cunning person who has made off with a fortune in jewels and other valuable items. Just who is this mysterious thief, and has Elizabeth really guessed his identity?

Nicholas agrees that Amelia would be the perfect wife for him, but he can't stop thinking about Elizabeth and the beautiful woman she's become. Will he accept his feelings for her before it's too late or will she marry his best friend?