As a late moon rises outside, nearby motion rouses Kino from his sleep. In the pale light, he is barely able to discern Juana, who moves toward the fireplace, quietly gathers the pearl, and sneaks out into the night. Kino stealthily follows her as she heads toward the shore. When she hears him in pursuit, Juana breaks into a run, but Kino apprehends her just as she is preparing to hurl the pearl into the water. Grabbing the pearl from her, he punches her in the face and kicks her in the side when she falls down. As Kino hovers over Juana, the waves break upon her crumpled body. He hisses menacingly above her, then turns in disgust and leaves her without a word.
As Kino makes his way up the beach, a group of men assaults him. Kino struggles violently as they paw and prod at him. As Kino drives his knife into one of his attackers, the men knock the pearl from his grasp. Meanwhile, some distance away from the fight, Juana gets up on her knees and begins to make her way home. Climbing through the brush, she sees the pearl lying in the path. She picks it up and considers returning to the sea to discard the pearl once and for all.
At this moment, Juana spies two dark figures lying in the road and recognizes one of them as Kino. In the next instant, Juana realizes that Kino has killed the man slumped by his side. Juana drags the dead body into the brush and then helps Kino, who moans about losing his pearl. Juana silences him by showing him the pearl and explains that they must flee immediately because Kino has committed a horrible crime. Kino protests that he acted in self-defense, but Juana argues that his alibi won't matter at all to the authorities. Kino realizes that Juana is right, and they resolve to flee.
While Juana runs back to the brush house to grab Coyotito, Kino returns to the beach to ready his canoe for the escape. He finds that someone has punched a large hole in the boat's bottom. Filled with sorrow and rage, he quickly scrambles back to his brush house, moments before dawn. As he arrives in the vicinity of the neighborhood, he notices flames and realizes that his house is burning. As he runs toward the fire, Juana meets him with Coyotito in her arms. She confirms that their house has been burned down completely. As the neighbors rush to control the fire and to save their own houses, Kino, Juana, and Coyotito duck between the shadows and into Juan Tomás's house.
In the darkness inside Juan Tomás's house, Kino and Juana listen as the neighbors attempt to subdue the fire and speculate that Kino and Juana have been killed in the blaze. The couple can only listen as Juan Tomás's wife, Apolonia, wails in mourning for the loss of her relatives. When Apolonia returns to her house to change head shawls, Kino whispers to her, explaining that they are taking refuge. Kino instructs Apolonia to bring Juan Tomás to them and to keep their whereabouts a secret. She complies, and Juan Tomás arrives moments later, posting Apolonia at the door to keep watch while he talks with Kino.
Kino explains that he inadvertently killed a man after being attacked in the darkness. Juan Tomás blames this misfortune on the pearl and advises Kino to sell it without delay. Kino, however, is more focused on his losses, detailing the destruction of his canoe and his house. He implores Juan Tomás to hide them in his house for a night, until they can gather themselves and make a second attempt to flee. Juan Tomás hesitates to bring danger upon himself but ultimately agrees to shelter them and keep silent about their plans.
That afternoon, Kino and Juana crouch together in silence, listening to the neighbors discuss them among the ashes outside. Most of the neighbors assume that Kino and Juana are dead, but Juan Tomás suggests that perhaps the family has fled to the south to escape persecution. As he moves back and forth among the neighbors, he returns to his house from time to time, bringing bits and pieces of provisions that will help Kino and Juana on their journey.
That evening, Kino tells Juan Tomás his plan to travel to the cities of the north. Juan Tomás advises him to avoid the coast, as a search party will be on the lookout for him. When Juan Tomás asks if Kino still has the pearl, Kino responds that he does and that he intends to hold on to it. At dark, before the moon rises, Kino, Juana, and Coyotito exchange parting words with Juan Tomás and Apolonia, and head out into the night.
Once Kino beats Juana, he begins to lose everything as rapidly as he gained the Pearl of the World. Kino loses his self-respect as a husband by beating Juana, his integrity as a law-abiding citizen by killing his attacker, his birthright in the form of the destroyed canoe, and his home, burned to the ground by an arsonist. Furthermore, Kino's senses become “dulled by his emotion” in his determination to overcome adversity and gain what he feels to be rightfully his by selling the pearl. He has lost the capacity to feel guilt, so he doesn't regret striking his wife or killing another man. As Kino's ambition to improve his family's lot strengthens, his ability to see to his family's well-being weakens. He exposes his son to questionable medical treatment and abuses his wife, all to achieve the material success he wants for them.
Kino's attempts to safeguard the pearl predispose him to violence in defense of his property. In the heat of battle, he loses control and succumbs to his basest human instincts: he murders his assailant. Once he crosses the line from defender to aggressor, Kino suddenly finds himself with nothing to gain and everything to lose. After Kino kills a man, the thought of improving his family is lost—the only thing that remains is to save himself and his family. Kino associates himself with his pearl, remarking to Juan Tomás that whereas he once might have given the pearl away as a gift, his many troubles have grafted the pearl to him. Kino sees the pearl as both a burden and a promise, and refuses to give it up.
Amid Kino's monomania (obsessive focus on a single idea), Juana remains tethered to and trapped in an increasingly disastrous situation. Though she sees Kino as “half insane and half god,” she cannot imagine living without a man. Because of her position as a wife in a traditional society, Juana is necessarily subservient to Kino. She must follow what he views as his larger ambitions, even though her good sense cautions against it as their situation becomes increasingly desperate. Unfortunately, although Juana's good sense demands that the pearl—the essence of her former hopes—be thrown away, her subservience leads her to drag herself up and return the pearl to her husband