European elites coexist with werewolves. Reyn Gray, Alpha Wolf King of the North, secretly controls security, mining, and sports empires while posing as a vagrant gamekeeper. Ella Hewitt, eldest Hewitt heir, is exiled north by her stepmother and stepsister Madeline, who steals her lover. Reyn rescues her in a blizzard and recognizes her as the legendary Moonlight Daughter. Bound by the Moonlight Pact and her silver whistle—relic, sanctuary key, and royal token—they enter a contract marriage. Reyn helps Ella reclaim her family, uncover her mother’s death, and defeat hunter families and hidden capital. She becomes revered Moonlight Mistress.