The family sits down to dinner. Jody's grandfather immediately makes reference to his wagon train days, mentioning how hungry he would get on the trail. He repeats things he has already said about Billy Buck's father, Mule-Tail Buck. He talks on and on. When the rest of the family finishes the meal and is ready for dinner, grandfather's plate is still full. Carl Tiflin interrupts him to suggest he finish his meat. After dinner, when the grandfather begins to tell the story about how the Indians stole the wagon train's horses, Carl remarks that they've heard the story, but he feels his wife's anger and asks the grandfather to tell the story anyway. Jody senses how the grandfather must feel, knowing himself what it feels like to be deflated by Carl Tiflin. Soon the family breaks up to go to bed, and Jody lays awake thinking about buffalo on the Great Plains.
The next morning, Jody wakes early to get a stick to use to beat the mice out of the haystack. Seeing Billy, Jody remarks that the mice have no idea what is going to happen to them. Billy replies that no one knows what is coming. The two go in to breakfast; the grandfather is not there yet, as he takes a long time to get dressed and brush his whiskers. Jody's father begins to openly complain about the grandfather, saying that he needs to realize that westward expansion is over. Suddenly, the grandfather appears in the doorway. He has heard everything. Carl immediately apologizes, and Jody looks in shame at his mother. It is not every day that Carl Tiflin takes back something he has said. Jody imagines that it is tearing him apart. The grandfather urges him not to apologize, saying that he might be right.
After his father leaves, Jody nervously asks his grandfather to tell more stories, but his grandfather replies that he is not sure whether anyone wants to hear them. Jody wants to go hunt the mice with his grandfather, but his grandfather would rather sit on the porch. Jody goes to beat out the mice, but loses interest and returns to the porch. He sits for a long time, until suddenly his grandfather begins to talk. He says that he's no longer sure whether crossing the plains was worth it, and that what really mattered was not getting anywhere in particular, but simply moving, in a snake-like line of humans. It was important to him to be the leader of the people. Jody says maybe someday he too can be a leader of the people, but his grandfather replies that there's no territory left to explore. His father is right; every place that could be explored has already been explored. This saddens Jody, and he offers to make his grandfather lemonade. At first his grandfather is going to refuse, but he sees that Jody wants to comfort him and accepts.
This section highlights the weakness inherent in Carl Tiflin's rigid sternness and pragmatism. When he offends the grandfather, even he realizes he has done something terrible. Whether the grandfather's stories were long-winded or not, they do not overwhelm his earlier accomplishments in leading a wagon train across the plains: his stories have basis in fact. Carl, who has always been distant, now seems blindly, heedlessly cruel. His lack of imagination comes to seem more than pragmatism; it is a coldness of character. In his shame and anger, and his love for his grandfather, Jody is clearly dissociated from the father whom he has so long esteemed. However, once again, the moral world of the story is not quite so simple. In his conversation with his grandfather, it becomes clear that, sadly, perhaps Carl is correct. The grandfather clings to his stories, to the veneer of adventure, but he is now uncertain of the actual purpose of that adventure. In his statement that they moved for movements sake, is simultaneously the assessment that they moved simply because they had to, and that they moved for adventure's sake. It was important to the grandfather to be a leader, and he was a leader, but that heroism did not make his life an ideal thing; instead, he clings to his memories of the past much the way America clings to its heroic memory of the West. Carl is exposed as overly, perhaps fatally, cold; but his pragmatism is more at home in the modern world than is the grandfather's clingy idealism.
In the grandfather's admission of his own uncertainty about westward expansion is a larger commentary on the American West, which is perhaps the ultimate subject of Steinbeck's fiction. When Jody longed to explore the mountains, and Gitano romantically dashed off into them, sword in hand, to die, adventure seemed like an ideal destiny. But Jody's grandfather feels that the age of adventure is closed. In another sense, however, he affirms the idea of adventure by saying that what was important about crossing the plains was not that at the end he was in California, but that leading a wagon train was adventure in itself. The adventure of crossing, of "westering" as he puts it, was what was important—it didn't matter where the westering ended. This is a theme akin to historian Frederick Jackson Turner's frontier thesis, which held that America constantly defined itself against the frontier it had yet to conquer. With the physical frontier gone, Steinbeck seems to suggest, one might easily become like Carl, cold and pragmatic, since the adventure of the west no longer existed. The book ends on this note, with Jody having to face the loss of his last illusion. He has learned of death and the brutality of life, and slowly had his visions of his life as a cowboy in the west torn from him. But though his grandfather himself is stuck in the past, his grandfather's words offer what may be a way forward; the "westering", the adventure, was the thing. It did not matter what that adventure entailed. His words as he sits sadly on the porch, in conjunction with the death of Gabilan, Gitano, and Nellie, must also be taken as a warning: adventure into the outside world is important and vital, but it does not promise uncomplicated happiness.