Axis, a gigantic coiling tree 1000 miles tall, stretches high above the clouds. At its center is a village whose people are in mortal danger because Axis is withering; its sap is drying up. The people beg their gods for help, to no avail. Young Kaena (voice of Kirsten Dunst) has strange visions, and is convinced that Axis is calling her for help. Compelled by a mysterious force, the rebellious, high-spirited teenager defies her tribe's taboos and the Grand Priest's supreme authority to take the perilous journey through Axis and discover what dark secrets lie beyond the clouds. Helped by a mysterious creature from another world, Kaena discovers a frightening truth that will profoundly change her forever.