After a dying criminal confesses that his loot has been stashed "in the tower", the Hardy boys make an astonishing discovery.,

The House on the Cliff is a gripping mystery novel from the renowned Hardy Boys series, authored by Franklin W. Dixon. In this thrilling tale, brothers Frank and Joe Hardy, along with their best friend Chet Morton, find themselves drawn into a perplexing case that leads them to a secluded cliffside mansion with a dark and mysterious past. The story unfolds when the Hardy boys receive a cryptic message from their father, Fenton Hardy, a renowned detective,...

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

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,...

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...

CAN THE HARDYS PASS THIS EXTREME TEST OF ENDURANCE AND SKILL? Making it to the finish line of the high-endurance Fire Creek Mountain Race is going to be a real challenge for the Hardys. The five demanding events include downhill mountain biking, kayaking, cross-country hiking and climbing, biking through the city streets of Montreal, and a high-speed SeaZoom race on Lake Champlain. But when dangerous accidents begin to interfere with the events,...

Joe, Frank, and their friends search the icebound Cabin Island for a missing boy and some stolen medals.

Joe and Frank investigate the disappearance of their friend's father when the plane he was flying disappears over the Adirondack Mountains.