Highway trouble -- Motel knockout -- The False Face Society -- Treasure below -- The ghost driver -- Masked stowaway -- No admittance, please! -- A flattened foe -- A close call -- Surprise connection -- Footsteps in the dark -- Trustworthy men -- A startled Seneca -- Hot on the trail -- On the brink -- Thieves strike twice -- A telltale cobweb -- Smashed evidence -- Lendo's dilemma -- A rebellious youth.

Suspecting that their friend has been swindled, the Hardy brothers investigate and find themselves on the trail of a much larger criminal operation.

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 Senecas' gold tribal relic Spoon Mouth. This startling discovery propels the teen-age sleuths into a series of perplexing and dangerous situations. Two strange-acting college professors, a valuable coin collection, and a taciturn Indian who refuses to discuss the mysteries surrounding Spoon Mouth -- all blend into a fast-paced story with several surprise twists that will thrill the vast legion of Hardy boys fans. - Flyleaf.