In the middle of the night, Princess Theti leaves the palace like a sleepwalker and rides to the Great Sphinx. Papyrus follows her to protect her, but when he finds her, she is the prisoner of the Sphinx, who is angry at the royal line for breaking their covenant and letting the sands cover the great statue. The Sphinx wants her life as sacrifice. Opposed by the evil Storm Man, Papyrus must journey to the Sacred Island to beg the gods for mercy.