Yakari 6. - The talking trees

Yakari and Little Thunder are walking through the vast forests when they hear voices coming from an ancient oak tree. To their greatest astonishment, however, it seems as if the tree is speaking to them. Yakari, who also understands the language of animals, is very happy that he can now talk to the trees in the forest. They don't even notice, but they travel a long way while following the voices of the trees. At the end of their journey, they reach a barren mountainside, where they come across the petrified remains of thousands of years old trees... Yakari and his steed get caught in a huge storm, while the little Sioux is most determined to protect the old trees from lightning. Will he succeed, does he really understand the language of the trees, or is there a much bigger mystery behind it?