On a trip to a retired police captain's country home, the boys and their friends find him missing and themselves plagued with mysteriously threatening happenings that seem related to an old local legend.
While flying, Nancy sees a car go off the road, and reports it. The bridge is out to that section of road, however, and the police don't believe her. Searching for the car leads her to a young mechanic, and a stolen car ring.
While investigating the disappearance of a missing scientist, the boys begin to doubt their senses when they discover an isolated estate loaded with bizarre illusions.
Nancy's eccentric aunts are selling their property. The day before the deal is reality, a burglar steals all the documents. When Nancy goes to her aunts to explain, she hears mysterious voices in the walls.
To raise money for charity, Nancy revives a play in a theater that is supposed to be haunted. Actors from the original cast return to do the play, but they are all acting suspicious, and Nancy is determined to discover the secret of the theater phantom.
Frank thinks he sees a girl who went missing years ago. When he tries to talk to her she claims that she is someone else. Frank and Joe soon find that she's mixed up in something illegal.
During a charity carnival, the wealthy hosts have jewelry stolen from their safe. A young Hispanic friend of Nancy's is accused, after having been seen on the property. Nancy believes the case has more to it than it appears.
While in Europe searching for their missing father, the Hardy Boys meet Nancy Drew and team up on a case that takes them to a rock festival in Transylvania held at Dracula's castle.
The Hardy Boys and Nancy Drew meet a group of musicians and Joe talks them into playing a gig at the Dracula's Castle festival, with Joe as one of the singers, so they can get in to search for their father.
On a trip to Egypt, frank and Joe finds themselves in a ploy of artifacts and smugglers, so it seems. In a confusing chase after a nameless girl the troubles looms around them. What is next??
While answering to a letter from an old friend, Frank and Joe ends up in superstition of something more than lights in the air. A disappearing boyfriend nd no trace, except ETs???
A man steals diamonds from a smuggler replacing them with fakes. Unaware, the fakes are given to a courier on same flight as the boys. The thief has drugged the pilots in hopes the flight will crash and fool the intended mob recipients.
Fenton calls the boys from Mexico. He needs them to bring his lock box. They arrive and think two girls are the contacts he said would meet them. But Fenton is held prisoner by a man who wants the contents of the box to hide his identity.
Nancy sees someone stealing a watch. The thief turns out to be a rich girl and a kleptomaniac. She is a competitor in Las Vegas' tennis tournament. Lots of jewellery around the casinos starts disappearing.
A deaf girl in Las Vegas sees a man on a call and reads his lips about bombs at a hotel. She and a friend tell the manager who doesn't believe her. Joe and Frank try to help them. The man realizes she can identify him so she is in danger.
A burglar dressed as Santa. A drifter in a stable next door, gets accused for burgling. Nancy don't believe that this gentle man is guilty, so she starts looking for clues. A mysterious car around. Who and what is going on?