Summary
The morning after Stanley found the golden object, X-Ray pretends to find the tube in his own hole, and gets the day off after handing it in to Mr. Pendanski. The Warden is very excited by the find, and supervises the boys as they all dig X-Ray's role, widening it and sifting the dirt twice to make sure they don't miss anything. Stanley realizes that they aren't digging to build character, like Mr. Sir keeps saying, but instead to find something for the Warden. Back at the camp, the boys joke about how the Warden has cameras all over the camp - even in the showers.
Zigzag is cold toward Stanley, jealous that he found the tube and obtained the approval of X-Ray. For the next few days, they keep digging in the same hole, without success. The mood becomes increasingly tense as the Warden gets more and more impatient, and Zigzag is hostile to Stanley, going so far as to injure him with a shovel. Eventually, the boys are moved to another part of the lake, and dig individual holes again.
Stanley receives a letter from his mother, and after defending it from the prying eyes of his tent-mates, he sits down to read what his mother has written. Zero asks him why he is laughing, and Stanley tries to explain, but Zero doesn't seem to have the same set of references as him, and so Stanley gives up. He learns in Chapter 18 that Zero can't read, but refuses when Zero asks for reading lessons, claiming that he is too tired after digging holes all day.
The next event that happens out on the lake is another example of Stanley being "in the wrong place at the wrong time" (85). Magnet steals a bag of Mr. Sir's sunflower seeds, and passes them around between the boys. When Mr. Sir returns, Zigzag throws the bag to Stanley, and it spills all over his hole.
Furious, Mr. Sir marches Stanley to the Warden's office, where he introduces the situation by saying that Stanley "found" something in his hole. The Warden is initially excited, thinking that he has found something important. When she realizes that Mr. Sir is trying to get her to discipline Stanley, her mood turns icy cold. She asks Stanley to fetch her nail polish, and begins to paint her finger nails with her home-made polish infused with rattlesnake venom. Without warning, she strikes Mr. Sir across the face. While Mr. Sir is writhing in agony on the floor, the Warden calmly tells Stanley to get back to his hole.
On the way back to his digging companions, Stanley thinks about his ancestor who was robbed by Kissing' Kate Barlow and left for dead in the desert, only managing to survive by taking "refuge on God's thumb" (93). No one understands what this means, least of all Stanley. The other boys are shocked that the Warden didn't punish Stanley for stealing the sunflower seeds. Stanley sees that his hole has already been dug; the boys tell him that it was Zero's work. Zero tells Stanley that he knows Stanley didn't steal the sunflower seeds - or the sneakers, for that matter, that sent him to Camp Green Lake in the first place. Stanley agrees to teach Zero how to read, and discovers that Zero is good at math and a quick learner, not at all the idiot that Mr. Pendanski makes him out to be.
As he lies awake on his cot that night, Stanley has an epiphany: the gold tube is a lipstick container, and the initials are those of the infamous outlaw Kate Barlow.
Analysis
There is an element of dramatic irony to these chapters, because the reader, like Stanley, knows that the team is unlikely to find anything in the hole. After all, the tube was actually found in a totally different location the day before. Sachar uses striking figurative language to describe how Stanley registers the real location in his mind, writing that Stanley "dug the hole into his memory" (71). There may be more dramatic irony in these chapters: readers have been exposed to the name of Kate Barlow in Chapter 3. It may be unlikely that a reader connects these dots, but it is possible, and if they did, they would be privy to a piece of the puzzle that not even Stanley figures out until the end of Chapter 22, when he realizes that the tube is a lipstick case.
The tension in the camp that results from the lack of findings and the Warden's impatience affects everyone, and Sachar's detailed description of Stanley's physical state underscores the desperation and tedium in Camp Green Lake as a whole. Stanley is "hot, tired, and sore," with barely enough saliva to lick the back of a stamp (82). His perpetual thirst ("It seemed that no matter how much water he drank, he was always thirsty") reflects the plight of the Warden in Camp Green Lake and the ongoing curse in the life of the Yelnats family (82). No matter how many holes the Warden has the boys dig, and no matter how much money or how many inventions the generations of Yelnats make, they will seemingly never achieve success. At this stage in the novel, the mood is one of repetition and even despair.
From a few details in Chapter 20, we learn the extent of the Warden's obsession with finding whatever she has the boys digging for. Stanley notes with surprise that there are holes close to the Warden's cabin of all shapes and sizes, and therefore presumably not dug by the inmates at Camp Green Lake. We can infer that the Warden has done the digging herself, which shows her desperation. The fact that she is more angry with Mr. Sir for getting her hopes up than with Stanley for disobeying his superior is also very telling. Chapter 20 leaves us with a strong impression of the Warden as a deadly woman on the brink of despair, who wields her power despotically and will do anything to get what she wants.
Stanley's resigned despair at the beginning of Chapter 22, when he contemplates how he will have to deal with Mr. Sir's revenge, manages to connect the past to the present, reminding us that for Stanley and his cursed family, the past is always with them. Stanley compares his situation to that of his great-grandfather, who was left for dead in the desert by the outlaw Kissin' Kate Barlow.
This flashback will actually prove useful in several ways for Stanley, and brings him closer to breaking the curse that plagues his family. First, bringing Kate Barlow to the front of his mind allows Stanley to connect the dots and realize that the object he found was Kate's lipstick tube. Secondly, he remembers how his great-grandfather survived the desert: by taking "refuge on God's thumb" (93). Of course, this still makes no sense to Stanley at this point in the narrative, but later it will prove instrumental in saving the lives of both Stanley and Hector Zeroni, and breaking the Yelnats family curse.