Ario, prince of Sandor, loses his father and most of his people in a volcanic eruption that blows-up their entire island. Ario is assisted by Maciste, the strong hero who was traveling by their land on the occasion, and they sail together in a long and dangerous voyage. When they land, they are captured by the Urias but when the Queen Amoha meets Maciste, she becomes friendly, and asks for help. Kermis, a Uria traitor, has joined the tribe of the Head Hunters and is slaughtering her people, though the warrior Taro has saved them from the annihilation. However, her father, King Olibana has been captured, and she fears for his head. Maciste tells her that he is protecting the tribe of Ario, already. When the Urias are attacked by the Head Hunters, Maciste finally decides to help the beautiful Queen Amoha.
—Artemis-9