After the new hydrofoil they are guarding is stolen, the Hardy boys face frequent danger in solving a mystery involving criminals who operate by

A chance meeting with a stranger on the road provides the Hardy brothers with a clue to a gang of local burglars.

The Hardy boys and their father solve a mystery involving inexplicable crashes of highspeed race cars being used to test an experimental turbine

As a final step in solving a mystery, Frank and Joe face the ghost at Skeleton Rock.

The Hardy boys travel to the Deep South to vindicate a long-dead Confederate general, disgraced during the Civil War because he was accused of st

Joe Hardy is kidnapped by a gang of jewel smugglers as a warning for the Hardy Boys' father to stay away from their operation.

The Hardy brothers solve the mystery of the missing inventor and recover some valuable missing jade.

Frank and Joe Hardy are determined to bring to justice the vicious criminals who kidnapped their detective father while he was investigating sabo

The Hardy brothers interrupt their investigations of jewelry-store holdups to answer a plea from their cousin on a New Mexico cattle ranch.