As a documentary investigating about the controversial phenomenon called "chemtrails", SKY tries to determine the origin of the persistent contrails crisscrossing the sky in many parts of the globe.
Are they normal contrails, are they used to prevent the global warming, could they be toxic, what would be their origin, which entity would be able to organize a global spraying and why?
Those are the questions asked throughout the documentary. To get answers the film asked the best scientists in the field but also activists, artists, military leaders, pilots, farmers and biologists.