During the winter, Karana makes a snare to trap another dog. She had seen one with gray fur and yellow eyes, and was sure it was Rontu's son. Karana catches a number of wild dogs with her snares, but none have yellow eyes. She does catch a fox, which hangs around her house and likes to steal abalones. Realizing that she will not catch the dog with a snare, Karana remembers toluache weed, which knocks out fish when placed in water. She digs some up and places it in a pool where the wild dogs like to drink, but it has no effect on them. Next she tries xuchal, which is made from ground-up seashells and wild tobacco. This works much better, and after drinking from a xuchal contaminated pond, the pack of dogs quickly falls asleep. Karana finds the gray dog with the yellow eyes among the sleeping pack and brings him home. She names him Rontu-Aru, "Son of Rontu," and the two become fast friends. Karana and Rontu-Aru chase gulls and go to Tall Roc just as Karana did with Rontu, Karana is happy, but thinks more and more of Tutok and Ulape.
Winter ends and very hot weather with little wind follows. One hot day, while Karana is on the beach mending her canoe with pitch, she wakes from an afternoon nap to the sound of distant thunder. The water level around the island is low, and everything looks strange and different. In the distance, Karana spies the crest of a large wave. Frightened, she runs along the sandspit, but soon the wave is crashing around her. She scrambles up a nearby cliff as quickly as she can, and watches as a second wave towers over the wake of the first. The second wave crashes against the cliff, and then washes back out to sea.
On her way back to her house, Karana notices many sea animals lying dead about the island. Rontu-Aru is very glad to see Karana return, and follows her everywhere around the house. Later that day, as Karana and Rontu-Aru are returning from the spring, the earth begins to move beneath them. They hurry home, and that night they listen to the sound of falling rocks around the island. The next morning, the earth is again quiet.
Karana's behavior in chapter twenty-six displays a surprising incident of hypocrisy. In the very last chapter, she had expounded her revolutionary opinion (at least for her tribe) that animals were like people, and that because they were she would not kill them. However, in chapter twenty-six, although she does not kill any animals, she does kidnap Rontu-Aru, something that is unacceptable treatment for a human and thus should be, by Karana's code, unacceptable treatment for an animal. Though Karana does not specifically state that she believes animals should be treated in the same way as humans, her language implies this position. The reader is lead to suspect that there is something odd about Karana's actions by the way she explain them. When Karana's snares do not work, she decides to use toluache weed, which she describes as "not exactly poison." The word "poison" sounds distinctly out of place; Karana does not seem like the type of person to poison anything. That toluache is "not" poison is not important so much as that Karana associated it with poison. The whole episode is out of character for her.
The earthquake in chapter twenty-seven breaks from the pattern of events that occur throughout the rest of the novel. While most of the chapters in Island of the Blue Dolpins describe Karana slowly building a home for herself on the island, reacting when necessary to the other inhabitants of the island or to the Aleut visitors, chapter twenty-seven describes a cataclysmic event that is completely beyond Karana's influence or control. Karana has been able to react appropriately to everything that has happened to her on Ghalas-at since she was stranded there, from fighting off wild dogs to hiding from the Aleuts. When the earth and sea rise up against her, all she can do is run in terror. Though the earthquake is not absolutely necessary to the plot, it does set up some of the action in the next chapter. Another may be to contradict the feeling of complacency that the reader has built up along with Karana over the course of the story. Karana has more or less mastered her island, and though she is living in harmony with nature, her achievements are an example of the power and resiliency of humans. The earthquake may have been included to show that Karana is truly at the mercy of nature.