RB144 Mystery Island

Bill, Stumpy, Henry and Mary Lu go camping on Lake Arthur Island. They meet fellow campers kindly Mr. Overby and grumpy Mr. Meany. Both men appear to be keeping secrets about themselves. On their very first evening there, Henry and Mary Lu hear some very strange sounds. The kids get scared and want to go home. What are Bill and Stumpy going to do to salvage their camping trip and get rid of the strange noises?