No man had ever penetrated the Great Thorn Forest until Tarzan of the Apes crashed his plane behind it on his solo flight. Within he finds a beautiful country. But in it lives the Alali, strange Stone Age giants whose women regard all men as less than slaves. And beyond the Alali lies the country of the Ant Men—little people only eighteen inches tall. There, in Trohanadalmakus, Tarzan is an honored guest, until he is captured by the warriors of Veltopismakus in one of the Ant Men’s wars. But unknown to the ape-man, they have plans for him—by the advanced science of the little people, Tarzan is shrunk to their size and set to work as a quarry slave.