One Monday morning, a thousand children leave the suburb of Farsta and go to Stockholm to occupy the Royal Castle. The children have formed a group called S.O.P.O.R. as a protest against the way adults treat them and have destroyed their future. They demand that the robots in the industry are replaced by humans to create job opportunities. They take the royal family as hostages.
Svante is a young boy who lives with his family in a Stockholm apartment. One day he meets Karlsson, a chubby little man in the prime of his life, who can fly using a propeller on his back and who lives in his little house on the roof.