The mystery of the tree-guard (#4)

The journey of Bi, Carter and Theodore continues! The next stop is a colorful Mexico! It is here that they hope to find the ancient city of Zavrolyudi and the mysterious wood-free tree, which was dreamed of finding the father of Bi and Carter. But the enemies who pursue them from the very beginning of the path follow them on the heels and expect to get the treasures of ancient civilization. Will it turn out to be friends of the lost city of Zhrolyudi and not to fall into the placed traps?