BACK TO BARSOOM! Tarzan of the Apes had been marooned on Mars once before. And it had proven to be one of the most terrible ordeals of his storied life. Returning to the warlike place its inhabitants called Barsoom was something the ape-man never expected to have to do again. But when colonists from the dying planet landed in Africa, claiming part of the jungle lord's rainforest as their domain, Tarzan knew that he must again brave that weird world to forestall a larger invasion of Earth. Fortunately, he has a powerful ally on the red planet. The former Captain John Carter of Virginia, now Warlord of Mars. Equally fortunate, John Carter has allies of his own. Together, they muster a fighting force equal to the stark necessity of finding the secret base from which interplanetary ships are launching. Can they interdict a second spacecraft in time? Otherwise, Africa will be only the first continent to fall....