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. In the old Montana mining camp of Lucky Lode, the young detectives puzzle over a series of mysterious events. A piano-playing ghost haunts the long-abandoned dance hall. Eerie blue lights flash from the hilltop cemetery in the dark...

"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!"--

"Frank and Joe are back on Black Bear Mountain, the scene of a previous wilderness adventure and mind-bending mystery. This time, the brothers are checking in on Dr. K, a friend they made during their first trip. Dr. K is a fan of living off the grid, but he's been MIA long enough to cause worry in the small mountain town. And so the teenage detectives Black Bear Mountain relied on before have been called in to help once again. It's not a good start...

When Haley Danelle learns that the friends on her MyFacePlace page's top eight are disappearing one at a time, she turns to Joe and Frank for help in finding them.

Brother detectives Frank and Joe search a hidden castle for clues to help them find a missing comic book in the nineteenth book in the thrilling Hardy Boys Adventures series.
Frank and Joe have been hanging out at Sir Robert's Comic Kingdom, the local comic and gaming shop, and got the exclusive invite to this year's Halloween costume ball at Bayport's one and only castle. Sir Robert plans to use the big event to unveil his most prized possession,...

When a rogue mentor agent within A.T.A.C. tries to kill them, Frank and Joe Hardy discover that the agent was being manipulated by malevolent forces who kidnapped his son, and the Hardy Boys have until dawn to find the child.

The Hardy boys dial a wrong number, get the Pentagon, and suddenly find themselves in a dangerous adventure involving national security.

While searching for the guard end of a broken saber that will solve one mystery, the Hardy boys become involved with a gang of bank robbers.

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.

The Hardy boys and two friends take a camping trip to the Rocky Mountains in an attempt to locate a gang of credit-card counterfeiters.