When Mr. Hardy disappears while investigating a mystery surrounding a vacant house rumored to be either haunted or an abode for criminals, Joe and Frank search for the truth.

When the Hardy Boys set out to solve the mystery of their missing chums, they discover a gang hide-out in a cave on an island along the way.

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...