The robbery of the treasure in the tower proves to be an exciting challenge to Frank and Joe. Frank and Joe attempt to foil a ruthless espionage ring in their effort to sabotage the United States space program.

"Now with a brand-new look, this is an edition that collectors won't want to miss! In The Secret of the Caves, the seventh book in the incredibly popular, long-running series, Frank and Joe Hardy discover the secret of the Honeycomb Caves while searching for a missing professor. A special treat for Hardy Boys fans and any reader who's new to the series!"--

"Now with a brand-new look, this is an edition that collectors won't want to miss! In The Mystery of Cabin Island, the eighth book in the incredibly popular, long-running series, Frank and Joe Hardy encounter several dangerous setbacks as they search for Johnny Jefferson and some antique stolen medals. A special treat for Hardy Boys fans and any reader who's new to the series!"--

"Drop case or else danger for you and your family." This warning addressed to Fenton Hardy not only alarms the famous investigator and his detective sons, but also puzzles them, because Mr. Hardy is working on more than one case. Which one prompted the threat? When more ominous warnings follow, Frank and Joe suspect there is a link between the counterfeiting case they are investigating and a secret case their father cannot discuss since it involves...

When the hardy boys buy a Chinese junk for a money-making venture, they discover it has a serious flaw.

While investigating the theft of a valuable idol, Frank and Joe enounter a terrified business woman, a walking mummy, and a weird glass eye.

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

Caught in their motorboat the Sleuth by a sudden storm at sea, Frank and Joe Hardy are helpless when the engine conks out. Drifting farther from shore amid the tumultuous waves, the boys are relieved to see the lights of a yacht. But their SOS is ignored. The shrill sound of a siren fills the night air. Moments later, a helicopter drops an object alongside the Sleuth. To the young detectives' astonishment it proves to be a wallet containing two thousand...

In their motorboat the sleuths Frank and Joe Hardy search Barmet Bay for a dangerous stranger who has stolen a valuable boat. Suddenly, in the eerie fog, they spot the craft drifting aimlessly out to sea. What happens next starts the young detectives and their pal Chet Morton on an intriguing adventure that takes them to Mexico and into the comparatively unexplored desert and mountain regions of Baja California. The search for the meaning behind a...

When dogs and men suddenly disappear, and strange screams fill the night, fantastic stories of vengeful ghosts are almost believable. It is these strange happenings which bring Frank and Joe Hardy to the Pocono Mountains to help their father’s friend solve the mystery of Black Hollow. But when the Hardy boys and Chet Morton arrive at Captain Thomas Maguire’s cabin on the edge of the hollow, he has disappeared. Frank and Joe are determined...