When geologist Mr. Roberts, his wife and three children rent the isolated old Johnson place in lieu of a projected cottage, two of the towns-people discourage them: the real estate agent, Mr. Penderbeam, and the boat rental man, Jack Collins. A scrap of newspaper and some rusted revolver shells add substance to innuendo, and soon Steve and neighbor Chip, both eight-graders, are on the trail. They find a buried tin box and the robbers to go with it, even sneak back to watch the arrest of ""Fingers"" alias Jack Collins. In between there's a camping-boat trip and a cliff climb: to throw us all off there's the unfairly suspected Mr. Penderbeam, but his role isn't overdone. Typical but nicely written, nicely plotted young summer mystery, just the right length (and strength) for its readership.