The action takes place in a summer camp. The children are obsessed with the idea of building a ship.

The Soviet army is approaching the Bulgarian border. Many government ministers and army officers prepare to flee the country. The partisans take over the key administrative buildings. At the War Ministry, the commander of the armored brigade Major Essev hesitates between his sense of honor as an officer and his patriotic duty. He takes the side of the partisans.

Plamen's parents are separated. His father is an old river wolf, his mother a nurse in the big city. The boy's longing for his father keeps him going. His studies don't go well. One day Plamen sneaks onto his father's barge and secretly sets sail with him. On this long and very interesting voyage, Plamen befriends his father, and when they have to return to Varna, the boy is happy: he hopes that all three of them will be together again.

A small circus troupe wants to perform for the children in a small Eastern European town, but is prevented from doing so by the evil town boss. The circus' clown and his colleagues come up with a plan to defeat the boss and his men and put on a show for the kids.