After the discovery of a huge golden condor in the heart of a deserted city, Esteban and his companions sleep deeply . The thunder on the Andes and a brief earthquake wake them all. There are many concerns: for Zia, this shock is the result of the wrath of the goddess Pachamama. Sancho and Pedro, have eyes only for the golden Condor and the profit they will be able to make. Anyway, all admit that this city is not an ordinary place and Mendoza, accompanied by Sancho and Pedro, go to explore the basement. Tao thinks for his part that the Great Condor is the fruit of the genius of his ancestors: the Empire of Mu.
Suddenly, Kokapetl warns: a strange object is stuck in the beak of the golden bird . Zia recognizes a quipu, an Inca message. Esteban climbs on the Great Condor to seize it . Tetanized because of his vertigo, Tao joins him. Both land inside a cockpit and Tao underlines a resemblance to that of Solaris. The boy recalls their first goal: to recover the quipu. Tao suddenly shrieks: he slipped and finds himself hanging on the Great Condor's beak , several meters above the ground. Esteban tries to help him, in vain. Tao manages to get the quipu but he falls. Luckily, Mendoza catches up with him and saves his life .
Tao gives Zia the quipu to decipher it. The girl says that a great danger was approaching the city and that the inhabitants fled to the Maya country. In addition, the Great Condor would have been able to help them. All are wondering about the meaning of this message: a danger? And how could the Great Condor have been able to help the inhabitants?
Sancho and Pedro suddenly reappear, out of breath. They claim to have discovered a secret corridor. We then discover a hatch leading to an underground walls decorated with mysterious patterns. Our friends borrow it and notice an intensifying heat as they go down. A light and a thud appear and they arrive at the heart of a crater with molten lava . They understand then that Pachamama Mountain is actually a volcano, about to erupt. A new earthquake is felt: without waiting, all flee to the exit of the tunnel by which they entered, this one collapsing behind them. They are fine, but this is just the beginning of the eruption .
The group then moves towards the exit of the city, but Kokapetl warns them that the giants Urubus approach Mendoza suggests to take refuge inside the city. Quickly, the Spanish retrieves the two pendants of the children, which has the effect of triggering the closure of the stone walls of the city.
If our friends are now protected from the Urubus, the volcano for its part grow louder and louder. Cracks open and the walls of the temples begin to collapse . Mendoza orders the troop to take refuge in the temple, which is also gradually collapsing.
Suddenly, an opening in the roof lets in a ray of sunshine on the Great Condor. The bird lights up and lowers slowly to the ground . Their survival instinct and their confidence in the Empire of Mu pushes them into the cockpit. The breath of the eruption violently ejects the golden bird into the air and destroys the temple .
The whole mountain explodes and the Great Condor begins a long descent in free fall. Our friends are wondering how they will pull through this situation. Zia notices a location representing the emblem of the sun. Esteban places the medallion found in the temple hall. Suddenly, the dashboard illuminates , the cockpit closes and the wings of the Condor unfold. The Great Condor raises his head and rushes in the air : our friends were once again saved by the sun ...