When Carol and Johnny learn of the Ollamat, an ancient stone that can channel savage magic, they convince their parents to take them to the cloud forests of Oaxaca. With Pingo's help, they search for the legendary city where it has been protected for a thousand years. But the twins aren't the only ones hunting for the Ollamat. After it is stolen, they must travel through an emerald mirror into the beautiful yet dangerous Tlalocan: the paradise of...