Life felt a little dull to Robert Justice as he returned to his teaching profession, especially after his experiences during the past summer. So when Little Eagle invites him and his friends Mirakeem and Becky to visit him in his hometown of Paradise, Robert Justice jumps at the opportunity. He knows that wherever Little Eagle is, adventure and excitement can't be far behind. The three friends discover that Little Eagle's family includes two separate tribes: the Wisnooks, a group of sheepherders; and a second lost tribe, who in times past found shelter in an extinct volcano and remain hidden there to this day. Robert, Mirakeem, and Becky are given the honor of joining the annual pilgrimage of the Wisnooks to Spirit Mountain. What begins as a relaxing vacation soon leads into the depths of Spirit Mountain, and to an unexpected discovery of a long-lost secret. The three friends must combine their wits with Little Eagle's talents to uncover the mystery of what lies beneath the mountain.