The rise of the Tzalekuhl Empire threatens to disrupt the peace that has lasted for generations across the land of Mezo. When the conquest begins, a young girl named Kyma witnesses the death of her father, Hegol, a tribal leader who refused to yield. As the solar eclipse nears, Kyma must unite the various tribes against an emperor determined to make them all kneel before his god or be sacrificed.
Kyma awakes to discover she is a captive of the Tzalekuhl empire. Roden reveals to her their reason for seeking revengs and what her father did when they arrived as refugees. Meanwhile, Itzabé and his friends discover the World Tree thanks to the help of the large tree creatures known as the Arbath'a.