After spending the morning picking onions and preparing for their journey back to Camp Green Lake, Stanley listens to Zero talk about his mother. Zero says they used to live in a real house, and his room was yellow. His mother used to sing the same lullaby that Stanley sang to him. Zero isn't sure why they had to move out and live on the street.
The lullaby offers more evidence that Stanley and Zero are more connected than they initially thought, whether or not they ever realize that. That again acts as a way for the novel to show that fate and destiny are at play in their lives.
Stanley and Zero's plan is to leave early the next morning, arrive at Camp Green Lake before dark, and then dig in the hole where Stanley found the lipstick tube overnight. Then, regardless of what they find, they'll leave after hopefully stealing food and water. Stanley thinks about his parents and wonders if they've been evicted for the smell of Stanley's dad's experiments. He wonders if they'll be homeless, and wonders, too, if the camp told them he's missing.
When Stanley isn't sure if the camp told his parents that he's missing, it suggests that he is coming to a better understanding of the fact that Camp Green Lake doesn't exactly operate within normal rules and regulations that govern the formal justice system.
Stanley and Zero head down the mountain the next morning. Stanley points out where he found the shovel, and Zero is impressed that Stanley carried him so far up the mountain. Stanley, who is carrying the sack of jars filled with water, slips and begins to slide down the mountain. The onions spill but finally, Stanley is able to stop himself. Miraculously, the jars don't break, and the boys are able to collect the onions they lost as they continue down the mountain.
The "miracle" of the jars remaining intact again suggests that destiny is on Stanley and Zero's side as they go on their quest. The fact that Stanley slips in the first place alludes to the possibility that this quest isn't going to be easy, even with nature on their side: nature still has the power to ruin things for them.
At the bottom, Stanley and Zero ask each other if they're thirsty. Stanley lies and says he isn't, and he thinks that this is becoming a contest between them. Neither of them wants to be the first to drink. They carefully climb down the cliff and again discuss drinking, feigning worry for the other. Finally, the boys decide to drink together. They find the Mary Lou before noon and sit in its shade to rest.
As Stanley and Zero engage in this argument, it's worth noting that they're engaging more in a fight against each other than against nature itself. This shift suggests that Stanley and Zero will be tackling human foes in the next part of their quest rather than natural ones.
Zero says that he has no idea why Zero's mother left him. As Zero talks, Stanley thinks that Zero is explaining this to himself more than to him. Zero says that his mother used to ask him to wait for her while she went off alone. Zero would hug his stuffed giraffe, Jaffy, while she was gone. Then, he says, she left him at a park and didn't come back for a month. The boys eat onions and drink, and then discuss which direction to go to reach Camp Green Lake.
The relationship that Zero describes with his mother makes it clear that Zero absolutely had someone to care for him at this point in his life, even if the particular ways she cared for him were sometimes questionable given their homelessness. Regardless, it opens it up for Zero's mother to still be out there to care for him.
Zero continues his story as they walk. He says that once, a few weeks after Zero's mother left, some kids about his age had a birthday party at the park. One girl invited him to play, though Zero knew he didn't belong. He noticed one mother who stared at him as though he were a monster. When one boy offered Zero cake, the mother told Zero to go away and told the other kids to stay away from him. Zero says he ran away so fast that he forgot Jaffy. Stanley asks if Zero ever found Jaffy, and Zero admits that Jaffy wasn't real. Stanley thinks of how awful it would be for his parents to not know if he was dead or alive, and thinks that's how Zero must've felt.
With Zero's story, the novel suggests that when it comes to children, they're naturally kinder and more accepting of difference; it's the adults in charge who have the power to create an environment that treats Zero like a monster. This suggests in short that cruelty is something that people learn as they grow up, likely from their parents. When applied to the Warden, this suggests that she may be so cruel because others were cruel to her.
Zero stops suddenly and insists they're going the wrong way. He draws a map in the dirt proving his point and Stanley follows him, even though he doesn't think it's right. Later that afternoon, a cloud rolls overhead and casts shade. Finally, Zero stops Stanley and asks him to listen. They can hear Camp Green Lake and, specifically, Mr. Sir. As the boys approach some holes, they decide to climb into them and wait. Stanley and Zero wait until they can't hear anything and then creep silently towards camp. Stanley feels a rush of fear as he sees the camp, but he manages to point out the hole where he found the lipstick tube. He and Zero hide and wait for nightfall.
The cloud here is notable; remember that it hasn't rained over Green Lake in more than a century, and the clouds have taunted the boys at camp for the entire novel. The cloud's presence then suggests that something important has shifted in nature, implying that change is on the way for Camp Green Lake. Stanley's fear illustrates how deeply he's internalized the terror of the camp, given that he feels the terror even when he's not a victim.