Deep in the jungles of the Central American Republic of Hidalgo, lies a stange valley cut off from civilization. Formed eons ago by a strange devilish chasm, it has roughly the shape of an egg. It lay unexplored for centuries, but was finally penetrated and explored by Doc's father, Clark Savage Sr. in 1913.  He and his partner Hubert Robertson were the first white men to enter the home of the lost tribe of ancient Mayan royalty. 

Doc's father befriended the wise old Mayan leader, King Chaac who extended his great hospitality to the explorers. The two men taught each other their respective languages and became great friends. Eventually, Clark Sr. told the King about his son, Clark Jr. and of his hope to mold the boy into a higher form of man. He explained to the King that he himself had taken the life-purpose of aiding the oppressed, and of his heartfelt desire that his son continue the work. After long personal deliberation the King and Doc's father forged a pact:

The boy's training would be completed and in 20 years when he is matured, the fabulous wealth of Mayan gold would be divided as such--

• 1/4 to be given to the government of Hidalgo.
• 1/3 to be set as a trust fund for the Mayan tribe, administered by Doc himself.
• The remainder, nearly half, to Doc Savage for his use in his career of aiding the opressed and punishing evildoers.

20 years later:

In Doc's initial adventure,  The Man Of Bronze,  he learns of his father's death by a strange menace known as the Red Death. A letter from his father written weeks earlier, gives Doc his first clue that his father has left him a fabulous legacy in the Republic of Hidalgo.

Doc and his men journey to Hidalgo and to the Valley Of The Vanished, where they are welcomed by King Chaac and his beautiful daughter, Princess Monja. Doc learns that they are the surviving ancestors of the Mayan civilization. He also discovers that they are in the midst of a terrible epidemic of the Red Death and are in fear of a mysterious figure know as the Feathered Serpent.

Doc skillfully thwarts the Feathered Serpent and develops a sereum to combat the Red Death, which is a particularly virulent strain of jungle virus. As thanks, King Chaac and his people accept Doc and his men as members of the tribe. Doc and King Chaac spend several days recounting memories of Doc's father, then it is time to go. Especially sorry to see Doc go is Princess Monja, who has fallen for Doc in a big way. What she does not realize is that she will see Doc again.

Doc and his men learn that a sinister figure known as The Leader has found the secret of Doc's fabulous wealth of gold, and intends on stealing it and using it in his plan for world domination. Doc and his aids speed to Central America to defend the Mayan tribe and the gold.

There they find themselves fighting against The Leader's army of trained soldiers of fortune, who bring to bear all the horrors of modern mechanized warfare. Airplanes, artillery and machine guns all but destroy the capitol of Hidalgo. Then they roll on toward the isolated valley of the Mayan gold.

King Chaac and his people, helpless against the onslaught, are relieved when Doc appears on the scene. King Chaac proclaims, "I am glad you have come in our time of danger." But, none is more happy to see the Bronze Man than the beautiful Princess Monja. She is still in love with Doc. "I was afraid," Monja sobs, "but I am not afraid now." Doc tells her gravely, "You must never worry or be concerned ever about my fate."

A fierce battle is waged, but Doc plays to the greed of the soldiers. Drunk with desire for wealth they break ranks and rush into the gold vault below the great golden pyramid, where Doc traps them. The Leader had planned to do this very thing with Doc, his men and the Mayans. His plan was to destroy them there. But instead, Doc did the trapping. In his rage against his troops for their utter defeat, he detonates the explosives in the cavern, killing all of his soldiers. With Doc closing in, The Leader ends it all by taking his life with his own hand.

The Leader's plan was to throw billions of dollars in Doc's Mayan gold on the international market in one big sweep, causing the financial security of nations to be upset. His soldiers would then have caused revolts, with The Leader stepping in as Dictator.

After insuring that the Mayan people of Valley Of The Vanished and the gold supply would endure, Doc and his aids once again said goodbye to their friends. Princess Monja stood silent and forlorn at the edge of the lake as the six men departed. The Mayan princess had eyes only for Doc.

But, Doc would return.