Antonio and the other children his age begin their catechism lessons with Father Byrnes that March. Antonio is very excited to learn about God and prepare for his first communion. Meanwhile, there are dust storms on the llano and the townspeople suspect that they are caused by the hellish atomic bomb, which is being tested out in the desert. The people condemn the bomb as man competing with the knowledge of God, and fear it will destroy everything. Antonio is frightened by the all-encompassing knowledge of God, but he still can't help desiring it.
Antonio still hopes for quick answers from communion, and his desire for knowledge grows. The atomic bomb symbolizes a real-life version of the apocalypses of the different religions, but also an example of the terrifying knowledge of God. When man wants too much knowledge it leads to destruction – this idea will later be connected to Adam and Eve in the Garden of Eden.
When Antonio reports these rumors of the atomic bomb to Gabriel, he laughs and says the dust storms are just the way of the llano, and the land showing that people have mistreated it.
The llano is losing its innocence, too. Gabriel, like Ultima, can see past clear-cut definitions of right and wrong – the dust storms do not have to be wholly good or evil.
On the day before catechism, Florence asks Antonio difficult questions about sin and fairness. When the other boys arrive, they ask why Florence goes to catechism class since he is an atheist, but he says he just doesn't want to be left out.
Florence seems to give voice to all of Antonio's doubts, and Antonio has no answer for his questions. This makes Antonio put even more unrealistic hope in his first communion.
Florence discusses his sad past and how if God existed he must be cruel and unfair. Both his parents are dead and his sisters work at Rosie's brothel now. God could have made the world a kinder place, and the only sin of Adam and Eve was wanting more knowledge. Antonio's faith is shaken, and he proposes that maybe God comes in cycles, and maybe when God is gone the Virgin or the golden carp rules in his place. There is a thunderclap as he speaks and Antonio fears that God is condemning him for blasphemy.
Antonio's doubts grow when he learns that Florence shares his sense of God's unfairness. Antonio's hesitant proposal here hints at his resolution to come, as he tries to reconcile and combine the religions of his culture. The sin of Adam and Eve – wanting knowledge of good and evil – relates to the idea that gaining knowledge means losing innocence, but also adds to Antonio's confusion, as he wants to receive such knowledge at his communion.
Antonio and Florence are late to catechism class and Father Byrnes warns Antonio about talking to Florence. Antonio goes unpunished, but the priest makes Florence stand in the aisle with his arms outstretched. In the sunlight, blond Florence looks like an angel. The class starts to recite the catechism, though some of the other boys whisper jokes. The class discusses mortal and venial sins and Antonio is frightened to think that you could die after missing just one mass and go to hell.
Even the priest is unfair in his punishments. Florence, with his angelic appearance and outstretched arms, is portrayed as an ironic Christ-figure here, since the Priest is punishing Florence because he knows Florence is a non-believer. Meanwhile, the other boys again parody Catholic solemnity with their antics, but go unpunished. Antonio is still preoccupied with the seemingly unfair, arbitrary rules of heaven and hell, and how small mistakes could have eternal repercussions.
Father Byrnes tells a story to emphasize how long an eternity in hell lasts. He talks about a huge mountain of sand being carried grain by grain across wide oceans by a single bird, and the time to move the whole mountain is just the first day of eternity. The children are shocked by the horror of this image, but Florence remains standing, unafraid.
Father Byrnes teaches them to fear God instead of to understand him, and in this the priest acts as a foil for Ultima, who advocates knowledge without judgment. The horrible punishment of eternity heightens Antonio's fears.