My Brother's Friend, My Secret Nightmare

At her seventh wedding, Anna Ashford is branded cursed by the Oracle, and her family swaps her out for her cousin Seraphine. A thousand-year-old blood pact binds the eldest Ashford daughter to the Shadow Lord if she is still unmarried on her twenty-sixth birthday, and that day has now arrived. Anna pleads with Julian to flee before sunset, but he dismisses the legend as a fairy tale and tells her parents everything, so they lock her in a tower. As the clock nears five, a warning insists the Shadow Lord is about to come for her.