Once, in a faraway land, a green thing squeezed out of the earth. The mysterious Tree Thing, which changes Marlo's life forever. Nothing grows in Marlo's valley, and it's a struggle to survive. But when his squirrel Rinti finds a glowing emerald acorn, it grows into a miraculous Tree Thing. Tree Thing changes everything, bringing life and hope. And when the shadowy Rider arrives with an axe, Marlo needs all his bravery and ingenuity to stand between triumph and disaster.