Millie, a baby nurse, and has been since she was seventeen years old. She is now about forty-five years old. She is in the waiting room at an employment agency, waiting to be assigned her next patient. She waits for three days before she is assigned to Mrs. Jones' daughter Joan, who she is to feed, change, and look after. Millie comes to think of the baby as her own, and while the other members of the household get on her nerves or treat her dismissively, Millie feels at home taking care of Joan. On Joan's behalf, Millie becomes upset at any disruption or noise that could wake her. She reprimands Johnnie, Joan's six year old brother, and is annoyed at Mr. and Mrs. Jones' dinner parties. As the story goes on, Millie also begins taking issues with how Charles, the house man, and Laura, his wife and the cook do their jobs, and tells Mrs. Jones her complaints.

At this point, Mrs. Jones had becomes fed up with Millie's complaints and threatens to fire her. Millie becomes terrified at the prospect of "losing another child." For a little while, there are no more incidents, but Millie's frustrations with the family continue to grow. Finally, Millie and Charles erupt into an argument and Mrs. Jones again tells Millie, that if she does not like the house, she should leave.

Millie's greatest fear is losing Joan, so she again does her best to stifle her discontent around Mrs. Jones and the other members of the family. However, a new problem arises for Millie when Joan begins learning how to sit up and use her voice. Millie understands that this is a sign that Joan is developing quickly, and that Millie's care will no longer be necessary. Millie's point of pride has always been that she gave her babies perfect care, but the stress she is under causes her to neglect the baby a few times. This creates more issues between her and Mrs. Jones and eventually, when Joan almost bumps her head, Mrs. Joan fires Millie.

As Millie gets ready to leave her post, she cries loudly and becomes so upset that Mrs. Jones begins to pity her, even inviting her to come back for the afternoon of Joan's birthday party. However, Millie is too upset at having lost Joan and says she can't come. Millie returns to the waiting room of the employment agency, where she waits in grief for three days, until she is assigned another little girl