The novel shows the gradual decline of the narrator’s mental state. She reaches the point of complete insanity when she tears down the yellow paper at the end. Having done so, she begins to think that she is the woman who has just been freed from the wall.
Detailed answer:
Charlotte Perkins Gilman wrote The Yellow Wallpaper to show the protagonist’s path toward insanity. The narrator’s physician is her husband John, who confines her to bed rest following postpartum psychosis. The protagonist is restricted from any physical or creative activity. Her only pastime is the secret diary. The narrator spends most of her time in a former nursery of a rented summerhouse. There is a yellow wallpaper in the room. Soon, the character becomes obsessed with it. She believes that there are secrets hidden in the mansion, so she wants to unravel them.
Confinement makes her mental state even worse. She begins to suspect that a mysterious woman israpped behind the wallpaper. The narrator’s obsession persists, and she decides to learn all the secrets of the mansion. In the climax, the narrator tears down the yellow wallpaper and, as she believes, frees the woman. At this point, she loses her mind entirely and begins to think that she is the one who has been released from the wall. John finds his wife insane and faints out of shock.