Explorer Academy The Tigers Nest Book 5

"On an island nation in the Indian Ocean, the explorers venture through a vast underwater world and take part in a friendly robotics competition. The team follows the Cruz's mother's clues to a magnificent tomb and center of spirituality precariously perched on the side of a cliff. There, Cruz is confronted by a familiar foe who's determined to stop him from completing his most important mission of all: Retrieving the final pieces of his mother's cipher"--Publisher.