Lilly is the littlest acorn in her family. But despite her small size, she dreams to one day grow to become as big and wise as Momma Acorn, her loving mother. But her brothers and sisters think Lilly is too small and will never be a large tree.
At the turn of the season, the winds whisk Lilly away from the familiar branches of Momma Acorn, and she finds herself in uncertain surroundings. She awakens Willie and Oakly, the oldest trees in the forest, and learns the value of believing with her heart.