Kino, a poor Indian fisherman, lives on the Gulf of California
with his wife Juana and infant son Coyotito. Their simple hut is
made of brush, and the couple sleeps on mats thrown on the dirt floor,
while Coyotito sleeps in a hanging box. Like others in their poor
village, they depend on nature for survival. Despite the poverty, Kino
is happy, honest, and hardworking.
As The Pearl begins, dawn is breaking. Kino watches the sun rise and
listens to the sounds of the morning. In his mind, Kino hears the Song
of the Family- an internal message that tells him all is well.

But within moments, a dangerous situation develops. A poisonous
scorpion stings Coyotito, and the baby's screams draw people from
all over the village. Juana insists that the doctor be called, but
Kino knows the physician is of Spanish descent and considers himself
above treating poor Indians. This does not satisfy Juana, who
announces that if the doctor will not visit the village, then they
will go directly to the doctor's house. Her independent spirit
amazes the villagers, who join in a procession that accompanies Kino
and Juana to the wealthy doctor's home. But the doctor refuses to
treat Coyotito because Kino is too poor. Kino is so angry that he
smashes his fist against the doctor's gate.

Later that day, while Kino and Juana are fishing in the Gulf, Kino
finds an enormous pearl- the Pearl of the World- and cries out in joy.
He believes the pearl will make him rich and enable him to provide
security for his family. But Kino discovers otherwise. The pearl stirs
envy in the villagers, and that night Kino is attacked in his hut by a
thief. The following day, he tries to sell the pearl to buyers in
town, but he is offered only a small sum of money for it. The buyers
all work for the same man. They know the pearl is worth a fortune
but hope to buy it cheaply by pretending that it is worth little.

In his anger, Kino says he will sell his pearl in the capital
city, where he believes he'll get a fair price. This amazes the
villagers because Kino has never traveled so far. After dark that
evening, Kino is attacked again. Juana is sure the pearl is evil and
will destroy the family. During the night, she quietly removes it from
the spot where Kino has hidden it and tries to throw it back into
the ocean. He stops her before she succeeds and beats her for
trying. As he returns to the hut, Kino is attacked again, this time by
two men. He kills one of them, and the other escapes.

Because of the killing, Kino knows that he will be hunted as a
murderer. As a result, he and Juana must leave the village
immediately. Before they can escape, however, their canoe is destroyed
and their hut is burned. They hide until the next night in the hut
of Kino's brother, Juan Tomas. The following evening, Kino and Juana
begin their flight to the capital. Soon they realize they are being
pursued by three people, so they flee up the mountain and hide in a
small cave. Their pursuers pitch camp in a clearing just below the
cave. Kino decides the only way to survive is for him to kill the
person on guard, take his rifle, and kill the other two, who are
sleeping.

Kino goes to the pursuers' camp and is about to attack them when his
infant son Coyotito cries out. Kino knows that he must spring
immediately at his enemies, but he is a moment too late and one of
them shoots toward the cave. There is a struggle and Kino kills all
three of his enemies. The earlier shot has, however, killed
Coyotito. The following afternoon the villagers witness the return
of Kino and Juana, carrying the rifle and their dead child. Without
a word to anyone, they walk through the village to the shore. Kino
lays down the rifle, takes out the pearl, and throws it into the
water.