Sheera is captured by the Cavern Creatures who take her to Kragor. Bollo returns to the village without Sheera and Little Rok so Tor knows something is wrong. Tor turns into Mightor to see if his friends need help. He discovers that the entrance to the where the Cavern Creatures and Kragor live is open and realizes that they must be to blame for his friends disappearance. Will Mightor be able to save his friends from Kragor and the Cavern Creatures?