When the wild Marquis of Veryan, the heir to a dukedom, is commanded by the Duke to take a wife or be cut off, he is certain all pleasure is at an end. But his mistress, Lady Elizabeth Sherreden, suggests a marriage with her sister-in-law. At first reluctant, Lord Veryan accepts a bet from his old adversary, Mr Waterhouse, to be married within the week. He proposes to Katharine Sherreden, and is accepted. All seems well, but Mr. Waterhouse is already plotting his revenge...