hardy boys (fictitious characters)

The Hardy boys investigate when a friend's plane is stolen at an air show, an event which triggers a crime wave.

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.

Frank and Joe solve a mystery involving the disappearance of a professor, a hot-tempered hermit, sabotage at the new Bayport Coastal Radar Station, and the Honeycomb Caves.