The Great Balloon Sabotage

When Clara Dewbell first entered her town's hot air balloon race, she was expecting a relaxing afternoon of friendly competition. But her peaceful flight took a dangerously mysterious turn when, out of nowhere, balloons started falling from the sky. Clara eventually catches an assortment of competitors, all of whom offer a different piece of the puzzle surrounding the strange nature of their balloons' sabotage, and the assailant behind them. With each new passenger Clara comes closer to an answer, but fewer and fewer balloons are still flying, and it's impossible to tell who will be next.

When you can see the whole open sky around you, what kind of saboteur can sneak up on you? And what do they want?