Jamie and Tom are back in Jurassic dinosaur world doing a spot of prehistoric bird watching. Suddenly a large face appears among the treetops — it's a huge diplodocus! The boys enjoy watching the enormous beast chewing on the branches, but when a big twig gets lodged in its mouth, the diplodocus starts going crazy. Jamie and Tom must find their way across the treetops, swinging on vines, in order to catch up with the dinosaur and try to help him.