Emily is on a secret mission for the King in the fifth magical mermaid adventure in the NEW YORK TIMES BESTSELLING series, now in a new edition with a gorgeous cover look. Emily and Aaron are sent on a top secret mission by King Neptune. The king has been having nightmares he doesn't understand and he knows only that Emily and Aaron must go to the Land of the Midnight Sun to avoid catastrophe. But when the friends arrive in this icy world of mountains and glaciers, they uncover a mystery more dangerous than they ever imagined. A magical adventure about the power of friendship.