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

Frank and Joe solve a dangerous mystery involving a payroll robbery, a mine cave-in, a piano-playing ghost and a booby-trapped helicopter.

Suspecting that their friend has been swindled, the Hardy brothers investigate and find themselves on the trail of a much larger criminal operation.

The Hardy brothers embark on a freighter trip under mysterious circumstances and find themselves involved with a smuggling ring.

The Hardy boys and two friends take a camping trip to the Rocky Mountains in an attempt to locate a gang of credit-card counterfeiters.

The Hardy brothers' search for the missing son of a wealthy industrialist leads them to Brazil and great danger.

When Frank and Joe Hardy investigate a hijacking, they become involved with industrial spies and a pursuit into the Canadian wilderness.

The Hardy brothers' visiting Greek pen pal enlists their help in searching for a priceless ancient Greek helmet loaned to and lost by a Hollywood movie company years before.

On a winter vacation in Jamaica the Hardy boys begin a dangerous adventure when an ancient bronze death mask is discovered near their beach house.