A chance meeting with a stranger on the road provides the Hardy brothers with a clue to a gang of local burglars.

Frank and Joe must take the shine off a jewel thief who sends ominous riddles in this Hardy Boys adventure. First a priceless painting disappears from the museum; then two ancient samurai swords vanish from a private collection. A string of robberies has hit Bayport, and all signs point to the Phantom, a recently released ex-con who last struck more than twenty years ago. There's only one problem: the Phantom has vanished into thin air, and not even...

When the Hardys' wealthy neighbor is robbed, Joe and Frank are asked by their father to help solve the case.

Bayport High's Green Environment Conservation Club is camping on Black Bear Mountain, but the bears aren't the only danger--rumor has it that a madman with a taste for human flesh lurks in the nearby forest. When the campers awake one morning to find a bear roaming the campsite, they also find that their teacher is missing ... and blood is streaked across his tent. Frank and Joe go in search of him, but can they survive the dangers on the mountain?...