It all begins when Grandpa Yólotl disappears. Matías, Claudio, Pato, Katy and loyal dog Duke uncover signs that will lead them to a great adventure, facing unimaginable creatures, astonishing characters – that once belonged to an ancient civilization, and a couple of rogue treasure hunters. The promise of their grandfather is the force that will guide these heroes, ready for anything, provided they always stay together and discover the secret of the jade medallion.

The story is about Katy, now grown up as a lovely butterfly, and her children, young twin caterpillars names Kiki and Koko, facing off against aliens who came to their forest searching for food which happens to be inhabitants of the forest. With the help of their friends, Katy, Kiki and Koko were able to defeat the alien X and save their forest and its inhabitants. The sequel to "Katy the Caterpillar."