Fourteen-year-old Stefan Kolbe, along with his mother and sister, moves from an idyllic small town to the developing area of Berlin-Marzahn, where his father works as a construction worker. Stefan must find his way in a completely new environment and surrounded by strange people. Stefan gets to know two girls, who attempt to seduce him, and gets himself into trouble with the landlord, who kisses up to societal authority figures. He becomes friends with the anxious Hubert, defends him against the constant humiliation of the older student Windjacke, and encourages him to stand up for himself. It ends tragically in a bitter fight between Stefan and Windjacke.
