Kino, is a poor Indian fisherman who lives on the Gulf of California with his wife Juana and baby son Coyotito. They are very poor but happy family. When he finds the "pearl of the world" he believes that wonderful things will come from selling it. As he tries to sell the pearl he realizes that the local businessmen will cheat him and decides to travel to sell it. When it is realized that Kino has murdered the man who tried to steal his prize possession the family is forced to run from their village. Trackers are sent to find them and, in desperation and rage Kino kills the men, not realizing that their gunfire has killed his son. The pearl was supposed to bring him happiness and money but instead it brings death and evil. In spite of being poor, Kino is happy, honest, and hardworking. Once he finds the pearl, his dreams for his son become a real possibility. His wife Jauna is quiet, respectful and cheerful. Jauna believes that the doctor in town can save her son from a scorpion bite. The doctor only is interested in the money he will be paid and tricks them into believing he has cured the baby. .
Not very long after leaving the village for the capital the family is tracked by three men with guns. They run up a mountain and hide in a cave. The people following them camp right below the cave that Kino and his family are hiding in. Kino decides that the only way to survive is to kill the person on guard, take his gun, and kill the other two. Kino goes to the camp and is about to attack them when Coyotito makes loud noise. Kino knows that he has to kill the bad guys quickly, but he is a second too late and one of them shoots toward the cave. Kino and the three men fight and Kino ends up killing all of them. The very first shot that was fired killed the baby. The next day Kino and Juana go home with the dead baby, the rifle and the pearl. They walk through the village to the beach; Kino puts down the rifle, and throws the pearl into the water.