When the Hardy boys eagerly agree to assist their friend Jack Dodd and his father in locating a family treasure, the two young detectives are unaware of the baffling complications that will arise. The only clue to the long-lost treasure is a cryptic message written by a Pilgrim ancestor. But when Mr. Dodd and Jack are accused of stealing cars and then mysteriously disappear, Frank and Joe are confronted with a triple mystery. Have their friends run away to avoid the law? Or are they secretly hunting for the treasure? Or have they been kidnapped? Despite mounting evidence and the bitter suspicions of the townspeople, the Hardys are convinced that the Dodds are the victims of a sinister plot. Clues that Frank and Joe uncover, with the aid of their jolly, plump friend, Chet Morton, lead to the secret hideout of a ruthless gang of criminals. Deadly road traps and aerial ambush, a spider man and a suspect who carries a menacing cane harass the young detectives as they seek the triple solution to this perplexing and exciting mystery. - Flyleaf.

Frank and Joe Hardy look for clues in this perplexing mystery.