Audrey and Aletta grow up separately, unaware of each other or their roots. But they are princesses of the kingdom of Essendor, and sisters at that! Many years ago, their prosperous country, guarded by a mysterious and magical creature - the Midnight Unicorn - suffered disaster: the royal couple was killed by the queen's exiled brother, and the newborn princesses disappeared. On the same day, the wonderful defender of Essendor disappeared forever. But the day will come when the truth will be revealed. And then the girls will find each other and go home to get back what is rightfully theirs, take revenge on the killer and... return the Midnight Unicorn to the world!