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.
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.