Esteban, Tao and Zia arrive at a lake that appears to be lined with gold. While investigating, the children are captured by the Doctor and Marinche.

Esteban and his friends inch forward over the plain of the land of the Mayas looking for the Swamp of the Rain God.

Having found the statue of the winged serpent, the gang continues into the forest only to find enormous cliffs when they emerge.

The Doctor and Marinche are spotted in the company of Teteola.

Esteban and his friends find the mountain they have been seeking.

The friends learn that the crystal tower combines heat and light to produce energy and that the Olmecs could use it to cause the volcano to erupt.