During a Polish language lesson, Mrs. Frał has a nervous breakdown. The hygienist sends her to a sanatorium. The teacher is replaced by the attractive Mrs. Jola. At the sight of her, Czesio cannot utter a word. Soon, the students are to write a love letter. Meanwhile, Mrs. Frał is feeling worse and worse, and the treatments are not helping her. Czesio, inspired, writes a letter by the river. Suddenly, a laughing Mrs. Jola appears with a stranger.