As the day falls on the lake, Mendoza proudly announces to Sancho and Pedro that he has spotted the location of the City of Gold, which enchants them. On their side, the Olmecs have captured Tao. Menator explains to Kalmec that the City of Gold, according to the indications of Esteban, must be on the island in the center of the lake.
On the shore of the island, Esteban and Zia lie inanimate. Strange people take them. Later, they wake up in the company of a man with a masked face. The man presents himself to them as High Priest of the Cities of Gold. His mission is to protect them against any outside attack. However, the arrival of the two children means that this mission is coming to an end ...
Meanwhile, Mendoza understands that the Olmecs seek to penetrate inside the mountain and wants to join them, accompanied by Sancho and Pedro. Esteban, Zia and the High Priest walk a long corridor leading to a sumptuous library. According to the High Priest, it would include a copy of every book written by mankind since the invention of writing. Fascinated, the two children follow the High Priest towards huge doors. He explains to them that they give access to the Mysterious Cities of Gold. After having shown them carved cavities on both sides of the huge portal, he invites them to place the centers of their pendants.
But the emotion of the two children is short-lived. Indeed, a man warns the High Priest that the Olmec war machine is nearby. Our friends do not hesitate for a second and go without delay to the outside. Menator appears and threatens to torture Tao if Esteban does not open the City of Gold. Esteban and Zia yield at the request of the old king. But the boy still poses a condition: only a few Olmecs will have the privilege to attend the opening of the City of Gold. This is how our friends return to the interior of the island with Tao, handcuffed and escorted by Commander Kalmec.
Reaching the gates, Kalmec threatens Tao with his sword and demands their opening. Esteban wants to understand why the High Priest leaves such a decision to Zia and him. He explains to them that this is the will of the Emperor of Hiva ...
Long ago, two great empires reigned on Earth. The Empire of Hiva, located in the Pacific ocean, as well as Atlantis, in the Atlantic ocean. Both of these empires were powerful and prosperous thanks to the control of solar energy. However, the war broke out between the two nations until the day when the solar weapon was used. The violence of the confrontation was such that it engendered the disappearance of the two continents. The emperor of Hiva, who had planned this disappearance, built seven cities of gold concealed in various places. In each of them he placed a Great Legacy, a source of energy equivalent to the heart of the Sun. These cities of gold were sealed by indestructible gates that only two pendants representing the sun could open. After several thousand years of oblivion, the medallions reappeared. The first, the one Zia wears, was transmitted from generation to generation in an Inca family. The second came to Esteban from a man from the great western ocean. The fact that these two pendants are now in the pure hands of two children is not the result of chance, but the wisdom of the Emperor of Hiva.
The speech of the High Priest is abruptly interrupted by Kalmec, who, impatient, again threatens to kill Tao. Esteban and Zia concede and decide by mutual agreement to open the City of Gold, in the name of friendship. The immense portal opens in a blinding light and the City of Gold appears to the eyes of all ...