Valya persuades her classmate Sonya to skip classes and go swimming in the river, where there is sun and freedom. She timidly agrees and, in order to justify herself in the eyes of the class teacher, writes her an explanatory note. But the love that Sonya dreamed of does not happen: having received the desired kiss, Valya loses interest in her. She could have kept silent, endured, but Sonya assesses the situation - yes, life does not always match dreams - and leaves in time. She returns to the class teacher with a guilty conscience, flushes the explanatory note down the toilet. It seems that this is a failure. But in the final scene she still smiles: this experience was not in vain. Everything will still be.