Timber wolves, a Rocky Mountain blizzard, and a mine cave-in are only a few of the perils Frank and Joe Hardy encounter during their search for the principal members of a notorious gang responsible for a payroll robbery. Clue by clue, Frank and Joe cleverly fit into place the scattered pieces of this dangerous puzzle and come up with the astonishing solution.

After receiving a call from her friend Helen Corning, Nancy agrees to help solve a baffling mystery. Helen's Aunt Rosemary has been living with her mother at the old family mansion, and they have noticed many strange things. They have heard music, thumps, and creaking noises at night, and seen eerie shadows on the walls.

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.

There is a crisis in Bayport! Soon the city will be without water! Every night, water strangely disappears from the new reservoir near Skull Mountain. Frank and Joe Hardy join forces with a team of skilled engineers to solve the baffling mystery.

In solving the mystery of two medallions missing from an inherited curio collection, the Hardys wind up in a desolate area of Guatemala at the mercy of dangerous thugs.

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.

The Hardy brothers' visiting Greek pen pal enlists their help in searching for a priceless ancient Greek helmet loaned to and lost by a Hollywood movie company years before. Danger is the name of the game when the Hardys agree to help their pen pal from Greece, Evan Pandropolos, search for a priceless, ancient Greek helmet. Years ago, Evan's uncle had loaned it to a Hollywood movie company for use in a silent motion picture, but the treasured helmet...

Suspecting that their friend has been swindled, the Hardy brothers investigate and find themselves on the trail of a much larger criminal operation involving the theft of an ancient Seneca artifact.