Extremists may resort to drastic measures to protect the environment, but did they really threaten the owner of a mall?

The Hardy brothers' search for the missing son of a wealthy industrialist leads them to Brazil and great danger.

When their father asks for help tracking a jewel thief, the Hardy boys find that the trail leads them back to their own hometown. There, they begin a new investigation of a mysterious death which occurred many years ago.

"In the past, victims seemed to have been children only. But since Frank was taken, who knows if anyone is safe? At this point, everyone is a suspect-- maybe even Frank."--P. [4] of cover.

Frank and Joe shadow teen superstar Justin Carraway to figure out the identity of his mystery stalker before events turn deadly.

Frank and Joe travel to New Jersey where they investigate a series of robberies at jewelry stores.

Frank and Joe travel to Los Angeles where they attempt to identify who is trying to murder rock star Madison Vee.

Frank and Joe investigate suspicious accidents at the Willis Firth Academy, a boarding school in New England, trying to determine who may be working to get rid of the headmaster and injure some of the students.

The Hardy brothers investigate injuries to students at the Rising Phoenix Martial Arts Center to see if they are connected and if someone at the school is to blame.

Young Frank and Joe Hardy enlist the help of their friends to solve a mysterious case involving a large number of frogs.