Nancy Drew and friends Frank and Joe Hardy are heading back home after a trip to Nassau on board Flight Alpha 6. They aren't in the air long before they overhear a conversation between the stewardess and a mysterious male passenger. The man identifies himself as Tom Jenkins of the Justice Department, and he's been following a man who's on the flight...but since boarding the plane he's lost track of the man.
Frank introduces himself, Joe, and Nancy to Tom Jenkins, offering their help. Having heard of the amateur detectives' reputation, Tom accepts, telling them he was hot on the tail of an American terrorist named Larry Niven, when he lost him on board the plane. Niven works for the People's Army, an organization dedicated to overthrowing the U.S. Government and may have a triggering device for nuclear bomb.
No sooner has he told his story, when Tom is suddenly taken ill with a terrible stomach cramp. Soon just about every one else on board is feeling likewise, including the pilot, Captain Merrit. Merrit is now unable fly and Frank, who is licensed to fly small craft, takes over. Nancy soon finds a woman named Alice Tandy, who has past experience with large aircraft, to replace Frank (since he has never piloted a plane of this size) and he changes to co-pilot.
Meanwhile, Nancy had discovered that according to the passenger list, one passenger is missing. Joe finds a bottle in a trash can, containing a small amount of mysterious liquid. Joe also finds a man's outfit in the bottom of a closet -- looks like the terrorist on the flight is in disguise.
Tandy and Frank land the plane without any mishaps, and are met by reporters and medical teams for the sick. The airline spokesman tells Frank and Tandy he's sending each of them on a free vacation, and they'll leave the airport via the VIP doors to avoid customs.
Why would someone poison the passengers? Why does the manifest say Larry Niven was on board, yet now he's missing? Everything suddenly comes together for Frank, who has been thinking about the missing terrorist again ever since the plane landed safely. What happened is: Niven and an accomplice boarded the plane; then the accomplice left after signing in and Niven disguised, so everyone assumed Niven was the one missing. The reason behind the poisoning was to cause an emergency that would suspend regular customs and security checks. Alice Tandy, hero of the day, is Larry Niven.
Niven attempts to escape, but is quickly overtaken by Justice Department agents. They then discover the triggering device in his "camera case".
- Doctor Benson
- Tom Jenkins
- Captain Merrit
- Larry Niven
- Susan Tully
Businesses and organizations
- Nancy Drew and the Hardy Boys Super Sleuths! #2 pages 165-188.