The eighth book in the adventure series by the most beloved children's author in the world. The Adventure gang – Philip, Jack, Lucy-Ann, and Dinah – embarks on a riverboat journey to a mysterious country somewhere deep in the East. The children, enchanted, watch the beautiful landscapes and the locals who seem to have come out of biblical times... But when their parents fall victim to kidnapping by Raja Uma, a mysterious figure with many faces, their journey takes an unexpected turn, and the strange river will lead them to dreamlike and mysterious places in a country that hides many secrets. Dangerous waterfalls, tunnels, underground caves, and an ancient temple with hidden treasures. Are you ready for... an adventure?