Caught in their motorboat the Sleuth by a sudden storm at sea, Frank and Joe Hardy are relieved to see the lights of a yacht. But their SOS ignored. The shrill sound of a siren fills the night air and moments later a helicopter drops an object alongside the Sleuth- a wallet containing...
Stranded by a sudden storm at sea, the Hardy boys discover a wallet containing two thousand dollars. Upon returning home, they learn that a truck loaded with rifles has been stolen. Even though the two events seem unrelated, they are but the first clues in a complex mystery.