Something is killing Pellucidar's greatest warriors, and Tarzan of the Apes will not rest until he has discovered the cause. Tarzan's hunt takes him deep into the earth's core, the very heart of the lost land of Pellucidar, where he finds himself the quarry of a strange group of beings: the trophy-hunting Predators! Unfortunately for the Predators, their code of hunting is a language the savage Lord Greystoke understands all too well.