 Netochka suspects some mystery from their past, and eventually a clue presents itself in the form of a letter that she accidentally discovers pressed between the pages of an old book in the library.It is a letter to Alexandra Mikhaylovna from a distraught lover, lamenting the necessity of their final separation, and grieving for the irreparable harm he has caused her reputation and her marriage.Netochka's discovery of the letter sets off a chain of events that bring Alexandra Mikhaylovna to the point of emotional breakdown, and Netochka to the point of womanhood as she confronts Pyotr Alexandrovitch with the truth of what he has done to his wife.