In this post-apocalyptic world nothing is more precious on the dry, sand-covered lands than fresh water. Desert covers all the known world; even the vast oceans have been overwhelmed by sand. Argos, hero of the Golden City and his companions Dito, Alma, and Ka have crossed the unfriendly sands to the Teacher's Tower, but Argos' teacher and the Tower's other inhabitants are under siege by the barbaric Deviants who, up until now, have been kept at bay by "The Big Lizard!"