While on spring break at South Padre Island the Hardy Boys set out to solve the kidnapping of a bullfighter who was plucked out of the bullfighting ring by a helicopter.
Working undercover for an Atlanta airline, the Hardys have uncovered an international terrorist ring bent on smuggling and murder. In Alaska the ring is preparing to square off against an ultrasecret government agency.
The murder of their father's friend, chemist Sam Gentle, has drawn Frank and Joe across country to northern Arizona where they try to track down the killer before the killer finds Sam's daughter.
Frank and Joe are the only witnesses to three shocking murders, but no one believes them, and they stand alone in a battle against an evil power that is determined to destroy them.
Frank goes undercover as a helicopter pilot and Joe goes undercover as a jack-of-all-trades to find out who is trying to destroy a floating oil rig in the Gulf of Mexico.
The art collector who suspects the Hardy boys of stealing one of his valuable paintings offers them a chance to prove their innocence by hiring them to find the painting and the real culprits.
Tom Swift has an encounter with an alien being. As a result an intelligence agency believes he is involved in a smuggling ring, so they send Frank and Joe to check him out.
The Hardy boys search for the group they hold responsible for their father's death. Phoenix Enterprises is an international combine of supersmugglers and the boys are in danger at every turn.
