Isabel gives Esperanza some last minute advice for taking care of the Pepe and Lupe as she boards the bus for her first day of school. For the first time, Esperanza is responsible for taking care of the babies as well as preparing dinner for everyone who is working during the day. Esperanza starts making dinner and feeds the babies plums, which makes them happy. Esperanza is feeling confident - that is, until the babies get sick from the plums and she burns the food for everyone else. Even though Esperanza has made mistakes, Isabel compliments the older girl for curing the children's stomach troubles with rice. Nobody mentions the terrible dinner.
Meanwhile, the harvest season for the grapes is coming to a close. All of the adults must work seven days a week in order to gather the last of the grapes before the autumn rains. Esperanza starts spending more time with her neighbors Irene and Melina, who is appears young and naive but is actually a mature woman who takes care of her husband and child.
One afternoon, when the men are working in the fields and the women are working in the shed, a dust storm descends on the valley. Melina and Irene instruct Esperanza to get inside and stay away from the windows. Esperanza worries about her family and friends as the dust seeps into their cabin.
Isabel returns from school unscathed, frantic about her kitten, Chiquita. Luckily, Esperanza has brought Chiquita inside to keep her safe from the dust storm. The women return shortly thereafter - they only had a few crates as shelter from the whirling dust. The men return moments later, caked in dirt.
When everyone is clean again, Alfonso explains that the dust storm has derailed the plans for a strike. Esperanza knows that no one in her immediate circle is going to strike because they need the money. She is glad when everyone returns to work the following day, as if the storm had never happened.
A month after the dust storm, Esperanza notices that Mama looks pale and encourages her to lie down. Her mother, tired and worn down, breaks out into a fever. A young doctor explains that Mama has contracted Valley Fever, a condition that results from dust spores growing in the lungs. Esperanza is rocked by the news that Mama will take six months to recover - and she may not even live that long.
The dust storm stops the strike, proving that nature still has power over man (and an entire valley of domesticated crops). As Alfonso explains to Esperanza, the dust storm reveals the unpredictability of Mother Nature - in strong contrast to the careful planning that has gone into preparing for the strike.
Nature further disrupts Esperanza's daily routine when Mama suddenly falls ill. Esperanza has already lost her father, her home, and has had to leave Abuelita behind in Mexico. Esperanza has finally been able to adapt to her new situation, thanks in part to Mama's support. Now, she must learn how to take responsibility and be strong for both of them.
Although some aspects of Esperanza’s life are changing, Esperanza is also growing more certain of herself. Even though her first day alone does not go exactly as she planned, she proves herself to be more independent than anyone believed she could be. Even though she has grown up in a world of privilege, she is able to take care of two small children and run a household on her own - at a very young age.
To this end, Esperanza’s narrative voice starts to sound more like a grown woman than a child. Instead of worrying about her clothes or dolls, she focuses on the taking care of the people in her life. There was a time when getting dirty was one of Esperanza’s biggest concerns, but during the dust storm, all she is worried about is the safety of her family and friends.
Additionally, Esperanza’s observations of the world around her become more astute. She is able to see Melina as both a young girl similar to herself and as a woman with the responsibility of a family. Straddling both worlds, Esperanza is similar to Melina in many ways.