Franklin W Dixon

Teenage detectives Frank and Joe Hardy investigate a case of counterfeiting.

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...

A series of bizarre events in their home town lead the Hardy Boys on a trail of robbers and kidnappers.

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

A banker who has been receiving threatening notes enlists the help of the Hardy boys. Before very long, the young sleuths find themselves entangled in the investigation of a notorious band of thieves.

The search for missing gold takes the Hardy boys to the Yucatán Peninsula where they uncover a second mystery.

In the Northwest Territories of Canada, the Hardy brothers and Chet Morton help to recover a stolen Viking relic.

Frank and Joe investigate the legend of Whalebone Island when they receive a warning concerning a sunken freighter

Racing cars! Mystery! Adventure! These elements combine to give Frank and Joe Hardy one of the most dangerous and intriguing cases of their careers. It all starts when their father, Fenton Hardy, is engaged by an experimental race car and motor designer to investigate a series of mysterious accidents. Three of his drivers have crashed because the windshields of their cars were suddenly crazed, thus cutting off forward vision. Frank and Joe uncover...

While searching in Iceland for a missing sailor sought by an insurance company, the teen-age detective brothers uncover a plot threatening the life of a United States astronaut and the secrets of NASA's moon project.