By the time the Walkers realize that one of their neighbors has sinister plans for them, they're banished to a primeval forest way off the grid. Their parents? Gone. Their friends? A world away. And they aren't alone. Bloodthirsty medieval warriors patrol the woods around them, supernatural pirates roam the neighboring seas, and a power-hungry queen rules the land. To survive, the siblings will have to be braver than they ever thought possible—and fight against their darkest impulses. The key may lie in their own connection to the secret Kristoff legacy. But as they unravel that legacy, they'll discover it's not just their family that's in danger . . . it's the entire world.