Hadron of Hastor, Padwar in the service of the John Carter, War Lord of Mars, goes alone in search of the beautiful Sanoma Tora when she is abducted by Tul Axtar of Jahar. But before Hadron manages to reach Jahar he is deflected from his purpose in an effort to rescue a slave girl of his own race from the ferocious green men of Mars. Tavia, for that is the lovely girl's name, leads Hadron to her home city Tjanath from which she had been stolen as a very small girl. Instead of receiving a warm welcome, both are immediately imprisoned. Hadron learns from a fellow prisoner in the pits that the Tjanathians must have mistaken him for a Jaharian spy and that all Tjanath is deathly afraid of Tul Axtar of Jahar for he has been breeding his race for 200 years to make a warrior army large enough to conquer all Barsoom. Moreover, Tul Axtar has a new weapon which will disintegrate metal. And Hadron already knows that a huge fleet of airships from Helium, headed by John Carter himself, will by now be on its way to Jahar in support of his search for Sanoma Tora--a fleet that is doomed to destruction!