This is the third adventure story from Gerald Raftery -- this time not an animal- and-boy story, and on that score with less of the emotional tug than its predecessors. He spins a good yarn, though not always a plausible one. And this time he has rooted his story in a sure-fire mystery with a scientific angle. Steve is a scholarship boy at camp, and an eager beaver when it comes to participation, with rocks his chief hobby, mineralogy his goal. His roommate, Jim, resents all that camp stands for, bucks the rules, refuses to conform, and finds, to his chagrin, that this gets him nowhere. Little by little he learns the hard way, and it is Jim's courage and daring (the moral issues involved are a bit questionable) that makes possible the scientific proof of the solution of the mystery of Copperhead Hollow.