When a famous millionaire asks young detectives Max and Maddy Twist to investigate who is sabotaging an international balloon race for charity, they find themselves competing against world-renowned balloonists--and one old nemesis. Reprint.

Features international detectives Max and Maddy Twist, who made their mark with The Chocolate Money Mystery.

The Deceivers

Asked by a Swiss banker to investigate a series of bank robberies committed by dogs, young detectives Max and Maddy Twist travel to Switzerland, where they discover that the man behind the robberies is none other than Professor Sardine. Reprint.

When her absent-minded inventor father suddenly remembers that he has five sisters, nine-year-old Harriet Bean, who has never heard of them before, determines to find her unknown aunts so that the unfinished family portrait can be completed. Reprint.

On the African game preserve where his father works, Akimbo devises a dangerous plan to capture a ring of elephant poachers.

Harriet helps her detective aunts, Thessalonika and Japonica, investigate cheating at the racetrack by disguising herself as a jockey. Reprint.