This story begins with a mystery that is most unusual. Then follows a long tour of Rattlesnake Mountain, taken by the boys of the Fox Patrol. There is a good deal of fun and adventure camping, fishing, and swimming, and the young heroes more than once prove their worth. Once they get lost on the road in the darkness, and find a curious cave. In the end the mystery is cleared away, and the lads show what it means to be prepared for any emergency.