Being of very strict morals, the teacher first carries the letter to the headmistress, and then instructs one of the pupils of the class to find out by whom it was written.

In the course of subsequent events, it is discovered that the letter was written by Boris Ramzin, to his classmate and deskmate Ksenia Zavyalova.

Classmates of children are understanding, but teachers and other adults differ in their views: some see in their relations a violation of decency and undermining of "moral foundations", some — a wonderful feeling in which you do not need to interfere, especially so unceremoniously.

Ksenia's mother, who repented of her behavior, makes it clear to her daughter that men have "one thing on their mind" and therefore she should not believe Boris.

Driven to desperation, she tries to poison herself, which classmates learn from one of the students in a German lesson.

Boris still loves the girl, but her feelings seem to be undermined as a result of the emotional trauma experienced.