The pin is the object with which Nastenka's blind grandmother fastens the girl's dress to her own, to keep watch over her without seeing her, and it stands for Nastenka's confined life: the concrete form of a loneliness opposite to the Dreamer's. He lives with no one; she lives clinging to someone.
On the Second Night, Nastenka tells that, after a mischief at fifteen that she does not reveal, the grandmother "took a pin and fastened my dress to hers" and said that they would sit like this for their whole lives, unless the girl became better. Two years have passed. Once she put Fiekla, the deaf maid, in her place, and Fiekla, not hearing what the grandmother asked, unfastened the pin and fled.
The pin organises the love story. It is because of it that the lodger sees Nastenka drag her grandmother's armchair and weep with shame, and withdraws with delicacy. It is against it that she rebels on the night of the bundle: "I said I could not live with my grandmother, that I would run away from her, that I did not want to be pinned with a pin". And it is because of it that, on the Fourth Night, she asks herself whether her love did not begin only because she lived under her grandmother's watch.
The object can be read in two ways. As a prison, it makes the grandmother a jailer and love a flight. As care, it is the eye that a blind old woman does not have, the only protection she can offer an orphan. Nastenka herself tells the punishment laughing and defends the grandmother right after, and the book keeps both things.