In prehistoric times, Mount Kilamanjaro is known as Great Sky Mountain to the peace-loving Ibandi people. One day, a boy named Frog Hopping on the Inner Boma clan witnesses a savage invasion by a neighboring clan in which many of his people are captured and enslaved. No he and T'Cori, a young woman training in the herbal arts, must scale Great Sky Mountain to consult with mighty Father Mountain--for it is ony he who can protect their future.