Cruel slave traders have invaded the jungle domain of Tarzan of the Apes. Now they head toward a fabled empire of riches that no outsider has ever seen, intent on looting its great treasures. And toward the same legendary land stumbles the lost James Blake, an American whom Tarzan has vowed to rescue. Following them, the ape-man comes upon the lost Valley of the Sepulcher, where Knights Templar still fight to resume their holy crusade to free Jerusalem.

Somewhere in the heart of Africa, a young archaeologist disappeared in the remote jungle mountains - Erich von Harben, son of an old missionary friend of Tarzan of the Apes. Now the ape-man seeks to rescue the lost scholar. The trail leads to a mysterious valley where Tarzan discovers two surviving outposts of ancient Rome, virtually unchanged by time. And there, Tarzan is thrust into the bloody gladiatorial arena, doomed to face every peril the cruel and corrupt emperor of Castra Sanguinarius can devise to ensure the ape-man’s death.

David Innes was a captive in Pellucidar, the strange world within a world that lies under the Earth’s crust. To rescue him, Tarzan comes into that savage, prehistoric land at the head of an expedition equipped with every modern device. But Pellucidar is not like the jungles the ape-man knows. Here are saber-toothed tigers and every savage creature from the beginning of time. Here the horizon curves back on itself and the sun hangs always in the middle of the sky. And now, for the first time, Tarzan is hopelessly lost in a land teeming with unknown, gigantic killers.

La was in trouble. The high priestess of the Flaming God in the ancient city of Opar—forgotten outpost of Atlantis—had been betrayed by her people and locked in the eon-haunted dungeons until Tarzan came to rescue her. La still loved Tarzan, but Tarzan brought her to his people and then left her. Now, together with a strange woman of Tarzan’s kind, she lies bound in the tent of an Arab slave trader, dreading her certain fate. Meanwhile, Tarzan is beset by a strange band of men who have invaded his land…led by a madman bent on evil subversion!

Evil men have come to the land of Tarzan of the Apes, looting and killing as they move. But other evil lurks in a small valley of the Ghenzi Mountains, where the last remnants of an ugly, perverted people dwell in what they call their faith—an ancient belief that came from Rome nearly 2,000 years before. Now they are wicked and many of them are insane. And now they have captured Lady Barbara Collis and mean to use her as a human sacrifice—unless Tarzan arrives in time!

When Tarzan of the Apes frees a man being tortured by cruel bandits, he is surprised to learn that the stranger comes from no race or country the ape-man knows. He is from the fabled land of Onthar, where lie two ancient cities unknown to the outside world. One is Athne, city of ivory; the other is Cathne, city of gold and evil. There great prides of trained lions are used to hunt down men and wage eternal war. And there Tarzan meets the beautiful queen Nemone, who is determined to have Tarzan as her king...or feed him to the lions!

Tarzan cared little for the fate of adventurer Brian Gregory, drawn to the legendary city of Ashair by the rumor of the Father of Diamonds, the world’s hugest gem. But to the ape-man the tie of friendship is unbreakable, and Paul d’Arnot’s pleas move him to agree to guide the expedition Gregory’s father and sister have organized for his rescue. The enigmatic Atan Thome is also obsessed with the Father of Diamonds, and has planted agents in the Gregory safari to spy out its route and sabotage its efforts.

When an American bomber crashes in the jungles of enemy-held Sumatra, the survivors face the perils of a completely unknown world…and the RAF colonel who flew with them as observer only seems to compound their danger by going mad—stripping to a loincloth and throwing away his weapons except for his knife. But for Colonel John Clayton, Lord Greystoke, the hazards of wild beasts and a remorseless enemy are a familiar and joyously accepted challenge—a chance to return to his true identity of Tarzan of the Apes.

Stranded on an uncharted Pacific island, Tarzan is forced to take command of an ill-sorted party—English aristocrats, a Dutch officer, a woman of doubtful reputation—to ensure their safety from a band of mutineers led by a madman. A lost colony of Mayans, avid for potential victims for their barbarous human sacrifices, only add to their danger. But the Lord of the Jungle has unexpected allies… Cast away with his band is a shipment of African animals unknown to the island, striking terror in the hearts of the Mayans and mutineers alike.