Under the watchful eye of the Mother Shrine, 12-year-old Wisp ekes out a simple but challenging life with Dad, foraging for food and losing herself in old books from the world that came before. She loves the Endless Forest - except when the Tree Walkers come for her.

In ages past, the great rain of fire and ash destroyed the earth, wiping out the ancients and everything they had made. Nature has reclaimed much since then, spreading out in a vast forest full of wonder and dread. Ever in fear of being taken away, she follows Dad's rules without question while learning to survive off the land.

No longer a small child, she accompanies Dad on one of his treks, her first time more than a few steps away from the cabin. A day exploring with him is the happiest time of her life, but joy is short-lived. A monster follows them home.

Safe in her haven, she hides while Dad goes outside to confront the beast. She wakes alone the next morning and waits. Alas, her hope of his return fades with the daylight.

Desperate, she breaks his strictest rule and goes outside alone. Not far from the cabin, she discovers his rifle abandoned next to the monster's strange footprints.

Afraid but determined, Wisp sets off on her own into the Endless Forest to find Dad - before the Tree Walkers catch her.