The Ruhr area in November of 1918. 13-year old Achim Wolters and his friends get their hands on some potatoes on the market. They want to surprise Achim′s father, who works on a mine sweeper boat, with a decent meal. But Achim′s father does not show up – an informer at the train station has betrayed him for his left-wing beliefs and has turned him over to the police. The priest tells Achim the sad news and advises him to pray for the release of his father. But when carpenter Stelzebein stresses that everybody has to take actions for himself, the devout boy at first does not believe in Stelzebein′s words. But then Achim witnesses in the prison how brutally the imperial police treat his father and the other inmates. Together with his loyal friends, Achim takes Stelzebein′s side. When the revolution starts, they stand together on the barricades.
Horst, a young boy from Berlin, spends his holidays with the "Pirates" at Horse Island. The teen gang is led by Horst′s friend Benno. Soon, Horst realizes that the pirates create a lot of nuisance. Gudrun, whom Horst meets on his way to the village, tells him that she has been attacked and injured by the pirates when she tried to observe a rare cormorant. Gudrun and Horst become friends. Since Benno is less than thrilled about this friendship, he plots a second attack on the girl.
