The end of school year and holidays are approaching. Tonda Navrátil (Michal Dymek), an 8th grade pupil, brought a live hen instead of vegetables as a model for a drawing lesson. Teacher Vambera (Jirí Pleskot) does not realize they are on the third floor and throws it out of a window saying: "Fly, bird, fly!" Teacher Bohousek (Ladislav Mrkvicka) driving off on his motorbike and catching sight of the flying hen has an accident. He breaks his leg and gets to a hospital. The cycling-trip to Slovakia originally planned by Bohousek for 8th grade pupils has to be taken care of by Vambera.