When Fenton disappears while in Europe, Joe and Frank go there to find him. Eventually they meet a Romanian police inspector who's working with their father. They also run into Nancy Drew, it seems that Fenton was working for her father and she came to find out what he learned. Eventually they find themselves in the village which is where Dracula from.
The boys and their father go to Africa to help find out who's behind some poaching. The prime suspect is a hunter who runs a Safari where most of the poaching is going on. But Frank falls for the man's daughter and doesn't believe he has it in him to do what they suspect him of. But when evidence against him is discovered he just gives up.
Joe and Frank are in Bermuda. Before they leave, a man who works for a someone who smuggles diamonds, needing money to pay back some people he owes, steals the diamonds and replaces them with fakes. His boss then gives them to his courier, a flight attendant on the plane Joe and Frank are on. So he goes to the airport and before it leaves, drugs the pilots, so while in flight, they pass out. So Frank and Joe try to fly but instead crash on an island and some of the passengers think they're in the Bermuda Triangle.
Fenton is in Mexico being chased by someone. He then calls the boys and tells them to bring something. And that someone will meet them but before he could tell them anything else, the one following him finds him. When the boys arrive and check into the hotel, two girls who are in trouble walk up to the boys and utters the words their father told them their contact would say. Later a man who claims to be a friend of their father approaches them but they don;t know him.
A deaf girl who's in Las Vegas with a friend, stops at a gas station. She sees a man in a phone booth talking and reads his lips. She then drives off, she tells her friend that the man was talking about bombs being planted at a hotel. So they go to the hotel and try to tell the manager who doesn't believe them. They run into Joe and Frank who tries to help them. Later the man runs into her and tells his accomplice about her so they try to deal with her.
Nancy drops her father off at the airport. She then goes home but is an accident. She runs into a guy. Later he is taken away in an ambulance and she is questioned by the police. But it turns out that the person she spoke was not a cop and all evidence that she was in accident was removed. So she tries to find out what is going on.
Joe is in Hong Kong with Frank and his father to help a friend of his father with a man's defection. Joe's in an accident and when he wakes up he is told that he's been in a coma for a year. He is then approached by a government agent who tells him that Frank and his father were killed when they tried to bring the defector in, possibly betrayed by his friend. He asks Joe about the details and he tells him. But Joe doesn't know is that he was tricked into revealing where the meeting is.
Frank and Joe go to New Orleans for Mardis Gras. And they manage to find a room. But a man, Mr. Dove for some reason wants them out of the room. So he asks someone to lift their wallets, hoping that they will leave but don't. And they run into Nancy Drew who's there on a case of her own.
While in Hawaii, Frank goes wind surfing and he sees a girl also wind surfing. When she flips over, Frank goes in to find her but couldn't. The police are convinced that Frank did nothing wrong so they release him. He later meets the girl's father who says that he hasn't seen her in two years. He asks Frank if he could find out what she's been doing. Frank who also wants to know who she is, and he learns that she's a remarkable girl but also has a dark secret.