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 .
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 .
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".
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 .
After leaving China under the threat of Zares, our heroes finally arrive in Japan. They must absolutely find there the third City of Gold against which the infamous Zarès promises to release Athanaos, the father of Esteban.