When Czesio and his three friends head to school, they are in for a surprise. A police patrol sets up a barrier to close the entrance to the school building. It turns out that the parents' committee, which always took place before the end of the school year, has been canceled. This is against the regulations, so adults and youth protest. Principal Frał sends Mr. Ziutek - formerly a maintenance worker, now a commandant - to fight them. The confrontation seems inevitable and erupts with increased force when the teacher orders the toilet to be closed.

The class is going to the lake. The students are supposed to swim and play pirates. Unfortunately, their plans are thwarted. The principal, her deputy, the hygienist and the children can't wait for the bus that is supposed to take them to their destination. And that's not the end of the unpleasant surprises.