The Joads travel across New Mexico and Arizona until the reach the Colorado River. Past the river lies the formidable Mojave Desert, and past that, California. The travelers set up camp by the river. Granma Joad rests, but babbles incoherently—she seems to be getting ill.
Not every Joad can handle the changes that come with their difficult journey, and Grandma’s health threatens to worsen even further.
At the river, Pa and Tom encounter a boy and his father, who are returning from California after being unable to find work there. The returning migrants warn that the fertile country of California is completely bought up. Arable land often lies fallow, and migrants will be punished for cultivating it. Migrants also face abuse from resentful locals, who call them “Okies.”
This is the first real indication that the land of plenty that the Joads seek in California may not, in fact, be the paradise they expected. The same arbitrary cruelty and selfishness that harmed the Joads in Oklahoma may still exist in California, after all.
Noah tells Tom that he can no longer go on. He is entranced by the water of the Colorado river, and plans to live off fish he catches. Tom tries to talk Noah out of his plan, but can only watch as Noah walks down the riverbank, growing further and further away.
Noah doesn’t value family as strongly as the rest of the Joads, and his strange demeanor is shown as the result of an asocial existence.
Granma raves in the stifling heat, yelling out at Grampa Joad. Rosasharn looks after her, and is distressed, but Ma Joad explains that birth and death are part of a larger process, and aren’t as lonely and painful as they seem. A Jehovite (Jehovah’s Witness) woman enters the tent and wants to give Granma her final prayers, but Ma Joad declines.
Ma Joad, like Casy, appears to have found an alternative form of spirituality that focuses on the unity of life and natural processes. Notably, Ma’s spirituality doesn’t mesh with the framework of established religions, as she denies the Jehovite.
A sheriff pokes his head into the tent that houses Ma Joad, Rosasharn, and Granma. He calls the family “Okies” and tells them that they aren’t welcome to stay. Ma Joad grabs a skillet and reprimands the man for his disrespect, and he moves on to the next tent.
Here, the Joads experience the bald-faced prejudice of the police for the first time.
The Joads prepare to leave quickly, fearing the cops. Tom tells Pa that Noah has left on his own, and Pa blames himself for the boy’s eccentricities.
Pa once again feels guilty for Noah’s behavior, though he isn’t in control of it.
Ivy and Sairy Wilson cannot continue with the Joads. Sairy’s health is deteriorating. She asks Casy to pray for her before the family leaves and he does so silently, without invoking God.
The moment of mutual understanding between Casy and Sairy underscores precisely the sort of unity that Casy believes in.
The Joads try to cross the desert in a night. A gas attendant that fuels them up warns them crossing the desert in their shaky jalopy is a risky proposition. The family continues along, and reaches an agricultural checkpoint. The checkpoint guards hassle the family, but back down when they see how bad Granma looks, and they let the car through. Ma Joad insists that the family cross the desert before stopping.
Ma Joad represents unyielding determination to cross the desert. Even the men at the checkpoint sense the Joads’ compulsion to make it across.
The family reaches California. Ma Joad reveals that Granma’s been dead since before they passed the checkpoint. Casy admires and fears Ma’s willpower; she stayed on the truck all night with Granma’s corpse out of love. Uncle John worries whether Ma has sinned, and Casy assures him that she has done nothing wrong.
Ma’s fearsome devotion for her family compels her to endure a harrowing journey. Here, the difference between John’s and Casy’s moral codes becomes apparent: John worries about the sin of lying, while Casy appreciates Ma’s altruism as the greatest good.