Fia the daughter of a piano teacher and Hampus the neglected nephew of a shoe maker are both mocked by the other children in the small village where they live,so they unite in retreating into a world of fantasy and challenge of their own.
Fia has given Hampus the white stone for letting the whole cobbler family go to the circus. She herself never had time to get a new assignment, because mean Malin came and drove Hampus away with a broom.
Hampus has completed his mission and laid an egg under the district chief's mattress, But Fia will still not give him the white stone. She thought it had been too easy for him to get into the district chief's bedroom.
Fia has promised Hampus that he would get the white stone if he removed an egg from under the district chief's mattress, while he was sleeping. But the district chief woke up and Hampus never got hold of the egg.
Fia and Hampus are hiding in a tree. They understand that the district chief and evil Malin will soon find them, and Hampus has therefore, as a last mission, asked Fia to collect a treasure, which they could live on if they have to flee.