Helen Plum Library

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

The Hardy boys dial a wrong number, get the Pentagon, and suddenly find themselves in a dangerous adventure involving national security Frank and Joe Hardy become involved in a case affecting national security when Joe dials a wrong telephone number and gets the Pentagon. Two words -- "Bombay boomerang"--That the boys hear before the line goes dead plunge them into a whirlpool of danger and intrigue. At the same time, their father is investigating...

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

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

While Frank and Joe help their father locate a notorious jewel thief, they also explore the mysterious death of a tycoon's nephew years before

Teenage detectives Frank and Joe Hardy investigate a supposedly haunted house reported to be the hangout of criminals

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

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

Frank and Joe investigate rumors that someone involved with Pinnacle College's top-seeded football team is being bribed to throw the championship game

With two cases in tow, the Hardy boys look to Turner mill for clues. Determined to learn the secret of the old mill, Frank and Joe employ a clever ruse to gain entrance, only to find themselves trapped