Danger is the name of the game when the Hardys agree to help their pen pal from Greece, Evan Pandropolos, search for a priceless, ancient Greek helmet. Years ago, Evan's uncle had loaned it to a Hollywood movie company for use in a silent motion picture, but the treasured helmet had been lost. At Hunt College, where Evan, Frank, Joe, and Chet Morton are taking a summer course in film-making, the boys are harassed by enemies who grow more and more vicious. Are gangsters hounding them to force Mr. Hardy to give up his investigation of an international crime syndicate? Or are the boys' sinister foes also seeking the helmet? Clues that the young detectives unearth keep them constantly on the move -- from college campus to California and finally to Greece. In a sizzling climax the Hardys, Evan, and Chet match wits with their powerful enemies on the island of Corfu. - Flyleaf.