The Hardy brothers investigate after reports of a beast attacking people. Is the Bayport Beast real after all?

When the Hardy boys reached the caves, they came unexpectedly upon a queer old hermit.

Detective brothers Frank and Joe investigate a stolen robot in the thirteenth book in the interactive Hardy Boys Clue Book series. Frank and Joe are excited to join Chet as he gets a preview of Robo Freeze, Bayport's newest sweet treat phenomenon. But Robo Freeze isn't just any ice cream shop--Sherbot the robot scoops and tops your cone to your exact specifications. But just before his big debut, Sherbot is bot-napped! Who'd want to sabotage Robo...

A banker who has been receiving threatening notes enlists the help of the Hardy boys. Before very long, the young sleuths find themselves entangled in the investigation of a notorious band of thieves.

"Frank and Joe are off to the Florida Keys to work alongside Lookout Shark Lab's Dr. E. Ella Edwards, one of the world's foremost marine biologists. On their first evening, Dr. Edwards paddleboards out to check on a lemon shark nursery. But after a sudden squall rolls in, she doesn't return, and the next day her board washes up with a shark bite taken out of it. The Hardys volunteer to help the search and rescue efforts as panic sparks a rift in Lookout...

"Frank and Joe are on a mission to track down a thief in the first book in an all-new, interactive Hardy Boys chapter book mystery series. Includes space for readers to jot down their own ideas and solutions to the case! Bayport Elementary is throwing a fundraiser so they can go on an end-of-the-year trip. Ellie Freeman's parents have volunteered their house for the event, and neighbors have donated all sorts of prizes to be raffled off including...

When valuable electronic parts are stolen from shipments made by Stanwide Mining Equipment Company's cargo planes, the boys go undercover as employees to track down the thief.

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...

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

Teenage detectives Frank and Joe Hardy investigate a case of counterfeiting.