This chapter returns to Mick's point of view. Mick says that she can no longer stay in the "inside room"; instead, she must either be around someone else all the time or keep her mind occupied by counting things. These days, she wants to follow John Singer around everywhere. She follows him on his long walks at night, but always stays far enough behind so that he will not see her. Mick only goes up to Mr. Singer's room twice a week because she does not want him to get sick of her.
The Kellys are very hard up for money now, as Etta is still sick and has lost her job. Mr. Kelly decided one day that he would advertise in order to get more watch-repair business. Mick helps her father paint a number of signs, and he puts them up everywhere. However, the signs do not appear to have much effect, and Mr. Kelly is very disappointed.
Mick starts to feel that there is something wrong with following Mr. Singer, so she tries hard to stay busy at home instead. She has made up her mind to forget about Harry, and in many ways she has indeed forgotten about him. He wrote her once, as he said he would, to tell her that he has a job at a garage in Birmingham and to ask her if she is alright. She answered with a card saying "O.K.," just as they had planned.
Nights are difficult for Mick because she does not have enough to keep her mind occupied. Because Etta is sick, Mick has moved into George's room. She tries to make George stay up so she will have someone to play games with her. Mick wants to tell Mr. Singer about what happened between her and Harry, but she does not know where to begin or whether he would understand.
Then, one day after school has been let out, Hazel comes home and tells the family that a job has opened up at Woolworth's; a clerk is leaving to get married. Hazel asks Mick if she would be interested in the job, but Mr. Kelly replies that Mick is too young and should be allowed time to finish growing up first. Bill and Hazel agree, and even Mrs. Kelly chimes in to say that she would rather keep Mick at home.
The family's protectiveness moves Mick, as she feels like it reveals that they all truly care for her after all. Mick suddenly says she would like to take the job. At first she is happy with her decision, but then she realizes that taking this job will mean the end of high school—once her family gets used to the extra income she provides, it will be impossible for her to quit and return to school. Mick worries about this prospect, so she asks Mr. Singer if he thinks it a good idea that she took the job. He nods, and she feels better about it.
Chapter 15 is told from Singer's point of view. It has been six months since he has seen Antonapoulos, so he plans another visit. Singer gathers together some gifts he has bought for his friend, along with a fruit basket and a box of strawberries. It takes him all night to get to Antonapoulos's hospital by train. Singer changes into a nice suit at his hotel and then goes over to the hospital, where a young orderly tells him that Antonapoulos is dead.
Singer, in a state of shock, wanders around the town listlessly until it is time to catch his train for the return trip. He works at the jewelry shop the next day, comes home, smokes a cigarette, and shoots himself in the chest.
McCullers does not make it clear why Mick can no longer stay in her "inner room." Perhaps because she has had to quit her music lessons, it is frustrating to continually think of music that is too complex for her to express adequately on paper. Alternatively, perhaps she is subconsciously worried about what happened between her and Harry. Whatever the reason, Mick begins to try to surround herself with other people all the time; when that fails, she occupies her mind with rote thoughts, such as counting the flowers on the wallpaper or figuring out the area of her house in square feet. Mick can no longer even turn to George, her once-faithful companion, as a playmate; he has grown distanced from her ever since the accident with Baby.
It does not appear—at least overtly—that Mick is upset about Harry. She claims to have forgotten about him; nothing about her behavior, save her inability to remain in the "inside room" of her thoughts, would indicate otherwise. However, because Mick is restless and cannot seem to find any sort of contentment, she begins following Singer around. As all the characters do, she turns to the mute in search of peace.
One of Mick's most heroic moments in the novel comes when she offers to take the Woolworth's job; this decision means she will have to give up playing the piano in the school gym, as well as most likely drop out of high school. Mick initially is happy with her decision because she knows it will help her family, but then, when she realizes all the sacrifice it entails, she is less certain that she has made the right choice. Only until Mick discusses it with Singer does she feel at ease; the fact that he seems to think she made a good decision is a huge relief to her.
Chapter 15 is the last chapter narrated by Singer. Upon learning of Antonapoulos's death, Singer feels he has no reason left to live. Even though Antonapoulos had never reciprocated Singer's feelings of devotion, Singer had been happy just to be in his friend's presence. Throughout the novel, McCullers has presented love as the only antidote to isolation; however, none of her characters except Singer is really unselfish enough to love another with complete sincerity. Furthermore, even though Singer truly and selflessly loves Antonapoulos, the Greek only responds to affection instinctively, as a pet or a baby would do. The attention Singer gives to the other four characters is partly love, but it is not complete because he does not fully understand the characters needs—nor do any of them conceive of Singer as someone who might also need reassurance. It is sadly ironic that no true communication takes place between Singer and his disciples. Indeed, they all remain egoists who never understand the motive behind the suicide of a man they have considered their closest confidante. Singer's last name in and of itself is ironic: he cannot even speak—let alone sing—his thoughts and feelings to most of the world around him.