Esteban, Zia, Tao and Kokapetl arrive in the heart of an arid desert. Suddenly, Kokapetl rings the alarm and they realize that two silhouettes, apparently Incas, pursue them. Esteban proposes to use a huge stump of dead wood to go down a steep slope and thus sow the pursuers. Fifty meters below, all three make a great glide and land in a cactus grove. The annoyance of Tao mixed with their pitiful state triggers a general laughter but they quickly realize that they did not sow the two strangers.
Just as exhausted, Gomez and Gaspard are once again sent by Pizarro in pursuit of the children. A messenger sends them a message from the governor who thinks that Zia will likely try to reach his village. Gomez approves and decides to go there. As for the children, they continue their journey in Inca land, in order to reach Puna, the village of Zia. Arrived at the top of a plateau covered by a thick mist, Zia feels disoriented and tired. The mist rises and hints in the distance a city lost in the mountains : Puna, Zia recognizes it! The children rush in it but the city is very quiet. Indeed, the city is empty of inhabitants and a bad surprise awaits them there: the commander Gomez and his men. The three children try to escape by hiding in the village temple. Unfortunately, Gomez is already waiting for them. The captain takes them prisoner and threatens to burn the village unless Zia translates the golden quipu. The girl refuses again and again. Then Gomez plays with Zia's feelings, threatening Esteban and Tao with death. She decides to speak: "Go to the High Peak, north of the village of Puna."
Gomez then sends a messenger to share the precious news with Governor Pizarro. In order to verify Zia's statements, Gomez decided to go to the High Peak the next day. The children spend the night in a small household in the village. In the middle of the night, the two strangers whom the children saw in the desert are back again: they are called Wayna and Ketcha. They are sent by the chief of the High Peak to bring them there. Relieved to deal with friends, the children flee through a secret passage hidden in the temple, which collapses afterwards. The secret passage taken by Wayna, Ketcha and the children leads them outside the village. The two men urge them: the road to the High Peak is still long ...