Dateless for the Christmas ball, 39-year-old bachelor, King Charles of Baltania, tracks down his American college sweetheart, only to discover Allison has never been married, yet raised a 17-year-old daughter, Lily, who mathematically might be Charles' biological princess.

A recently separated father and his teenage daughter become the deadly obsession of their neighbor -- a beguiling, deranged young woman willing to do whatever's necessary to take her rightful place as their wife and mother.