Carmen, 12, spends the summer break in the city with her increasingly confused mother. There are no other kids her own age, so she plays with two younger children. Their play is interrupted by Bengt-Olof, also known as Bengbulan, who terrorises and scares them. Carmen’s mother is getting worse and worse and leaves Carmen to her own devices. When the adult world fails, the children must stick together and take matters into their own hands.