Unfortunately, everyone is self-serving: the priest hears about the pearl and thinks about repairs needed for the church, the shopkeepers think about the clothes they could sell to Kino, etc.
Then the doctor realizes Kino was the guy from earlier, and he thinks about Paris and fine dining.
Then we cut to the pearl-buying offices. This is where all the "agents" sit around and haggle a man into taking the lowest possible prices for his pearls.
Even more depressing, these miserable scrooges are only buying the pearls on behalf of other (richer) folk.
Kino, we are told, becomes everyone’s enemy. Each person sees what the pearl could do for him, and Kino becomes the only man standing in their way.
But Kino and Juana are happily oblivious. They sit at home with Kino’s brother Juan and his wife Apolonia; Kino talks about what he will do once he becomes a rich man.
He decides he wants to get married to his wife—officially and in the church, now that they can pay for it. He looks into the pearl and sees a vision of them at the altar, dressed all spiffy.
Then he says he wants a rifle.
Kino continues: his son Coyotito will go to school.
But then he gets scared at his own talking, seeming to doubt the real capabilities of this magical pearl.
The priest comes to visit, but he’s super-condescending because he considers the natives to be children.
He flatters Kino and puts in his two cents about how they should donate money to the church.
Juana receives his words kindly, and the priest leaves.
Kino is distracted by the evil song, which is competing with the song of the pearl.
Once all the spectators have gone back to their homes for the night, Kino sits around and realizes that many are plotting against him.
He decides to counter-plot.
While he’s busy doing that, two men with lanterns approach his home: the doctor and his servant.
The doctor says he was out earlier, but now he’s come to look at the baby.
Kino tells him the baby is better, but the doctor counters that sometimes scorpion stings seem to get better when really they’re getting worse.
The doctor takes a look at Coyotito and is all, "Hmm! Hurmph! Well!" and says the poison is holed-up on the inside with blueprints and planning a second attack just as soon as it gets its beauty rest.
He then gives Coyotito a mysterious capsule, which we speculate contains poison.
The doctor goes outside, and Kino wraps up and hides the pearl. Good call, buddy.
Sure enough, the baby gets sick. Juana says "the doctor knew," but Kino is suspicious, mostly because of the evil song he’s hearing.
The doctor then gives Coyotito something else (antidote), packs up his bags, and asks when Kino will be able to pay the bill.
Kino is all, "As soon as I sell my pearl," and the doctor is all, "Ooh, you have a pearl? Really? Tell me more about this mysterious object that, before this very moment, I have not heard mention of whatsoever. Also, I’ll "hold" it for you in my "safe."
Kino passes on the offer, but not-so-intelligently lets his eyes travel to the place in the hut where the pearl is hidden.
Everyone leaves. Kino hears more evil music, so he moves the pearl to a hole he’s dug under his sleeping mat.
Juana asks who he is afraid of, and Kino answers, "Everyone."
They all go to sleep until Kino awakens with the song of evil pulsing through him.
What follows is a scuffle in the dark with at least one intruder: Kino gets smashed on the head, but chases off the bad guy.
As Juana nurses his injury, she declares that the pearl is a sin, that it’s evil, and that it will destroy them if they don’t throw it back into the ocean.
Kino, who is busy oscillating between fear and rage, doesn’t listen.
The next morning, Kino digs up the pearl and stares at its beauty while listening to its song. He feels hopeful again—today is the day he will sell the pearl.