Plot

Jan's communist father accused of murder, goes into hiding. Jan befriends Max who aids in search for truth. Max killed by Nazis. Jan flees on barge, meets Erika who helps him escape police and find his surviving father.

1934, Germany. Jan is a 13 year old boy, who is raised without a mother. His father, a communist, is accused of a political murder, and predicted to be shot by the police when he was on the run. Jan lives with his aunt and finds a friend, Max, who wants to help him to find out what really with his father happened. During a conspirative gathering Max is shot by SA (Nazi paramilitary) and Jan succeed to escape in a barge. Erika, the daughter of the captain of the barge, and a boatman hide him. They try to help Jan to escape from police and find his father, who really survived.—gelecegim

After the police tell thirteen-year-old Jan that his communist father is wanted for murdering an SA man, the only person willing to befriend him is Max, who is involved with a resistance group. Max agrees to help Jan figure out what really happened, but during a secret antifascist meeting, Max is shot and Jan barely escapes. The only clue he has is that a man on a barge knows the whereabouts of his father. While trying to find this barge, Jan's boat sinks, but the ship owner who rescues him is a loyal Nazi. Can Jan find his father before the police find him? Jan on the Barge is the final installment in a trilogy of historical children's films by director Helmut Dziuba, which also includes Red Ties (Rotschlipse, 1977) and When Unku was Ede's Friend (Als Unku Edes Freundin war, 1980).—yusufpiskin

Germany at the end of 1933: 13-year-old Jan, who has lost his mother, grows up with his aunt. He has been in correspondence with his father Karl for a year and finally sets off to meet him in Bitterholm. His father wants to pick him up at the train station, but he doesn't show up. Nobody opens the door at his father's address and a neighbor suggests that Jan's father has received what he deserves. When Jan realizes that a man he has already seen at the station is following him, he escapes to the nearest police station. There it becomes clear that the man following him belongs to the police. Jan's father is wanted by the police because he is suspected of murdering an SA man on December 16. His trail is lost at the water's edge, where his jacket was found, containing Jan's last letter.

Jan returns to his aunt shortly before Christmas, who is now being watched suspiciously in the village as her brother is suspected of being the murderer. Jan's mother was Czech, his father a communist and Jan is therefore considered an outsider by the young people loyal to Hitler. Only the older boy Max, who is in a resistance group and helps persecuted people escape to the East, supports Jan. He is also the one who makes it clear to Jan that his father could not have been a murderer: When the murder took place, his father was not even in the city, but was helping to bring a persecuted man to safety. The SA wanted to cover up a murder in its own ranks and frame a communist. Jan could only tell Hermann, the man on the Zille, more about his fate or whereabouts. As Jan remains skeptical, Max goes against the rules and takes him to the man his father had rescued and hidden in a forest hut near the Czech border. He confirms Max's report. A short time later, the hiding place is surrounded by SA men. The man and Max are shot, while Jan manages to escape.

He goes to the Elbe, where he thinks he sees the man described on the Zille. While attempting to transfer to the Zille Erika, Jan's boat sinks and he is pulled onto the barge by the boatman. Jan only regains consciousness days later. Sitting at his bedside is the girl Erika, daughter of the ship owner Wiese, who is loyal to Hitler. The bosun in turn introduces himself to Jan as Martin Liebig, but when asked about Hermann, he states that his name is Hermann Martin Liebig. The ship's crew is considered to be loyal to the line and so the police do not search it in their search for Jan. Wiese, who comes on board later, wants to betray Jan, but Martin makes it clear to him that he and Erika will also be betrayed. Jan remains on board as Martin's supposed nephew, but learns nothing more about his father except that he is a good man. When the mysterious professor comes on board to tutor Erika, Jan thinks he might be able to help him. He has previously heard that Martin is not the wanted man on the Zille and was only pretending to the boy out of pity. The professor, however, seems to have good connections. He is in fact a communist who was turned into an informer by the Nazis. The alcoholic finally gets drunk on board when the Zille is anchored in Magdeburg and threatens to betray everyone on board to the police. The Zille casts off and Jan finally pushes the drunk into the Elbe; the professor drowns. Wiese and Martin want to spread the word that the alcoholic went overboard without the others noticing.

Jan ends up confiding in another tugboat he had seen earlier. He turns out to be a contact who takes him to his father on another ship. He ends up traveling back upriver with him.