It is a time of magic, and a time of darkness. The fierce wars between the bats and the squirrels have been raging for many years, but tonight the battle for power takes an extraordinary new twist. The Starwife, leader of the black squirrels, lies dying; before she can name her successor, she is betrayed and poisoned by her trusted handmaiden. As the vicious bat army launches a devasting attack on the Starwife's realm, the squirrel leader staggers to a window and calls for aid. In a different corner of the land, Vesper the young bat and Ysabelle the squirrel maiden are as yet unaware of the events that will sweep them into a nightmarish journey to save their kind from destruction.