Franklin W. Dixon

Valuable electronic parts containing platinum are being stolen from shipments made by Stanwide Mining Equipment Company's cargo planes, and Frank and Joe Hardy are called upon to assist their world-renowned detective father to solve the baffling case. At Stanwide the boys pose as employees, and become suspicious of their boss's hostility toward them. Is he involved in the racket? And what is the truth behind the plane crash at sea in which Clint Hill,...

Two teenage sleuths help their detective father search for a famous rocket scientist whose disappearance endangers the launching of the Firebird Rocket.

The Hardy boys agree to help a friend and his father find a family treasure. When the friends disappear, the sleuths find themselves faced with two mysteries.

While searching for the guard end of a broken saber that will solve one mystery, the Hardy brothers become involved with a gang of bank robbers. Frank and Joe Hardy become involved in an intriguing mystery which revolves around their fencing master, Ettore Russo. Proof that Russo is the rightful heir to his grandfather's estate hinges on retrieving the guard end of a broken saber lost many years ago in California. The young investigators' quest is...

Frank and Joe solve a mystery involving a missing man, an abandoned airplane and giants in the desert.

Triggered by the disappearance of a brilliant young professor, this mystery takes the Hardy boys first to Kenworthy College, where they find a puzzling message on an examination paper. But then their pal Chet Morton, with his new metal detector, and buddy Biff Hooper, turn up a clue that sends the young detectives on an exciting search in another direction -- to the Honeycomb Caves, on the seacoast. A hot-tempered hermit who considers the caves his...

Frank and Joe Hardy are determined to bring to justice the vicious criminals who kidnapped their detective father while he was investigating sabotage of a road-building project in the Kentucky wilderness. After Mr. Hardy's amazing escape, the boys pick up a clue -- the word "Felix" mumbled by their sick father in his delirium. When they discover that the dossier of a notorious ex-convict has been stolen from Mr. Hardy's files, the two young sleuths...

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.

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