Lady Rowena Arrington has fallen in love with the man her sister must marry. When Viscount Craighorne invites the family to his castle for Christmas, Rowena knows she cannot avoid her host during the festivities, nor can she prevent the engagement planned to take place at his annual Christmas ball. As their evening of merrymaking draws to an end, Craig and Rowena meet beneath the mistletoe for one magical kiss.

Can the promise of true love embolden the young couple to defy her family's plans? Or will she and Craig settle into the separate lives expected of them, with only the memory of one shared Christmas Eve to keep them warm?