Kino is a poor pearl diver who lives in a small village on the coast of Baja California with his wife Juana and their baby Coyotito. He is a proud and resourceful man, but he is also deeply frustrated by his poverty and the injustices he faces. His life takes a drastic turn when Coyotito is stung by a scorpion, and he discovers a giant pearl that promises to change their fortune.
While not a "main" character in the traditional sense, Juana plays an equally important role in the story. She is Kino's loving and supportive wife, and she is fiercely protective of their family. She is more pragmatic and cautious than Kino, and often serves as his voice of reason.
While Coyotito is a baby, his fate plays a crucial role in driving the plot of the story, and his death deeply impacts Kino and Juana.
The story is also populated by several other characters, including the doctor, who refuses to treat Coyotito without payment, and the priest, who sees the pearl as a sign of God's favor.
The pearl itself is also a major character in the story, representing both hope and destruction for Kino and his family.