In the fifth book of the Magic Tree House series, Jack and Annie are whisked away to the Amazon rainforest. Their mission is to find a special fruit to help Morgan le Fay. Their adventure is filled with danger and discovery as they encounter giant ants, hungry piranhas, playful monkeys, and a sleek jaguar. They must rely on their courage and research to navigate the jungle, solve the riddle, and get back to the tree house before it gets dark.