Teenage detectives Frank and Joe Hardy investigate a supposedly haunted house reported to be the hangout of criminals.

The Hardy boys determined to learn the secret to the old mill employ a clever ruse to gain entrance only to find themselves trapped in a subterranean passageway.

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

"Bayport Elementary's annual science fair is here, and Frank, Joe, and their friend Phil are determined to win. But the morning of the fair, Phil discovers that their awesome homemade robot has gone missing!"--Page [4] of cover.

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

Frank and Joe Hardy look for clues in this perplexing mystery.

While attending an amusement park under the new ownership of their friend Daisy, Joe and Frank investigate the disappearance of a patron who was last seen riding a hit attraction, an event that has threatened Daisy's family's livelihood.

Teenaged detectives Joe and Frank Hardy uncover a plot to sabotage a ski resort.

Eating candy nonstop and watching TV all day sounds great... until you actually do it, as the kids of Bayport High find out when all the adults vanish, and the world's greatest (high school) detectives -the Hardy Boys and Nancy Drew! - have to team up to solve the mystery! Whether it's going undercover, sneaking out at night, chasing weird buses, or following a strange smell, they know it'll take all their wits and smarts to get their parents and...

A Nancy Drew and Hardy Boys mystery unlike any other you've ever read! When the teenage brothers Frank and Joe Hardy are accused of the murder of their father — a detective in the small resort town of Bayport — they must team up with Nancy Drew to prove their innocence (and find the real guilty party in the process) in a twisting noir tale, complete with double-crosses, deceit, and dames. Writer Anthony Del Col (Assassin's Creed, Kill Shakespeare)...