Frank and Joe visit the zoo where they find herpetologist Dr. Michaels collapsed from a snakebite and the new exhibit of Australian poisonous snakes stolen.
The Hardy boys, vacationing in Vermont, offer to help the police locate a missing camper and find themselves involved with a doomsday cult, a deadly strain of bacteria, and possibly the devil.
At the world-famous dolphin research center in Hawaii, the Hardys learn that a dolphin has a mysterious injury and one of the researchers has disappeared.
