Rarely do magicians reveal their professional secrets. Consequently Frank and Joe Hardy are amazed when a well-known magician, the Incredible Hexton, offers to reveal the secret of his “Vanishing Man Act” and invited Mr. Hardy to be the subject. When their detective father fails to reappear, his sons are convinced that something sinister is afoot, despite Hexton’s insistence that Mr. Hardy is playing a joke on them. While desperately searching for their father, Frank and Joe find themselves working with SKOOL, a U.S. organization of secret agents pitted against UGLI, an international ring of spies stealing government secrets domestically and internationally. The young detective’s gripping adventures culminate in a dramatic climax when they unmask the secret agent on Flight 101.

When an archaeologist who guards the priceless 1,000-year-old treasures of the temple of Angor Wat goes missing, her daughter Kate calls on Jack to help bring her home. No sweat for a top secret agent. Except this time it's personal. The archaeologist also has information leading to the whereabouts of Jack's missing brother. Now Jack must stop a power-hungry madman before the treasure, and the archaeologist, disappear forever.