Frank and Joe Hardy suspect that their best friend Chet Morton is the victim of a summer school swindle and offer to help get his money back. While probing a baffling burglary at the Seneca Indian Reservation in New York State they investigate Zoar College located nearby. Clues that Frank and Joe uncover indicate that there is a connection between the Zoar College swindle and the theft of the Seneca's gold tribal relic Spoon Mouth. Annotation Suspecting that their friend has been swindled, the Hardy brothers investigate and find themselves on the trail of a much larger criminal operation.