Sonny and Skippy are in the park when they hear an explosion in the air. They come across an unconscious pilot who has ejected from a plane. When Sonny gets into difficulty, he sends Skippy to get help.
An actor hired by Dr. Stark attempts to discredit Matt while impersonating him by running a car containing his boss and a Government Senator off the road.
While exploring a cave, Sonny and Skippy find a secret entrance to a valley that was thought to be uninhabited and inaccessible. There, Sonny befriends Tara, an old Aboriginal man living happily on his own.
An aggressive National Parks & Wildlife Service inspector arrives at the Waratah National Park determined to instill fear into everyone at Ranger Headquarters.