Mendoza and his two friends search for Zhu and Zia who joined him. Returning to the ship, Ambrosius and Tao surprise a man who tried to steal the Pyramid of Mu.
Li Shuang tells Esteban that his ancestors were the Atlanteans. Tao listens this information disturbs him as the Legend says that the people of Mu and the Atlanteans fought during a terrible war that led to their demise.
In the morning, Mendoza and the two sailors go in search of children. One of the henchmen of Zares pretends to know where they are and lead them in an ambush. But Mendoza is ready to fight .
Flying over the canyon in which Mendoza and two sailors fell, Esteban and Zia discover they have miraculously escaped death and ensure their rescue. Happy and relieved, they fly off towards Tibet.
Returning to the ship, Ambrosius and the children discover that Mendoza tried to steal the pyramid of Mu. Esteban can't believe in his guilt, and help him to escape with Sancho and Pedro.
Our heroes and Ambrosius enter the City using their medallions which missing parts were given to Esteban by Mendoza. Inside the Sacred Mount, Esteban calls the sun which chases the fog and illuminate the "City of Gold".
Panicked by the noise of the city that closes, our heroes are trying to run out in the middle of the foundations which are sinking into the ground - By rescuing Pichu, children lose track of Ambrosius .
Finally, our young heroes return to the Tibetan village where they find Ambrosius, waiting anxiously - In the evening, while the party is in full swing, Mendoza discreetly reveals to Esteban that his father is alive .