The Billion Dollar Ransom

The Billion Dollar Ransom is the 73rd title of the Hardy Boys series of mystery books for children and teens, published under the pseudonym Franklin W. Dixon. It was published by Wanderer Books in 1982.

Plot summary
The Hardy boys help out when a magicians' tournament is threatened by mysterious happenings. Frank and Joe naturally catch the magician who kidnapped the President and all culprits by slowly closing in on their position and taking control.