This book is about a poor, hardworking pearl diver named Kino. He lived a happy simple life with his wife, Juana, and baby-son Coyotito. But one morning before Juana had her breakfast and Kino was finished a scorpion stings Coyotito. After Kino failed, selflessly, to grab the scorpion. Then other evil things start to happen to the family and Kino hears the evil music, and the doctor won't cure Coyotito due to the fact that Kino doesn't have any money.
The very next day Kino and Juana set out, Juana walking behind Kino. Before they put the canoe in the water, Juana prays to God and says magic spells, so they find a pearl to pay for the doctor. Kino dives out of the canoe, which was handed down by his grandfather to his father and then to him, he sees the biggest oyster he has ever seen and grabs it.
Kino opens the oyster in the canoe and finds "The pearl of the world." Kino now thinks all his problems are over but little does he know his problems are just starting.
Kino goes home and tells his neighbors what he will buy once he sells the pearl. After the doctor hears that Kino has a perfect pearl he goes to cure the baby. The doctor cured the baby and asks Kino if he wants him the put the pearl in his safe, but Kino declines. Later that night, someone breaks into Kino's house and tries to find the pearl, but Kino bravely attacks the intruder before he can find it.
The next day Kino tries to sell the pearl, but the pearl buyers trick Kino by telling him the pearl is worthless. Kino realizes they are trying to cheat him out of his pearl so he walks...