Because he has engaged in one crooked deal too many, the immensely wealthy Phoney Bone, along with his cousins Fone Bone and Smiley Bone, is banished from Boneville. While fleeing from a wild swarm of locusts, the mismatched friends lose sight of each other. Now, each of the three finds themselves alone in a vast, strange wilderness. One by one, they stumble into a mysterious valley filled with puzzling, fearsome, and wonderful creatures. Unbeknownst to them, Phoney, Fone, and Smiley are about to embark on the longest and most adventurous journey of their lives.