When Felix returns, the Hoenikkers begin cleaning Papa's bedroom of all traces of ice-nine. They use brooms, blowtorches, dustpans, hotplates, and buckets to collect and melt down all the large pieces of ice-nine that fell onto the floor. They skim the floor with the blowtorch. They also decide to build a funeral pyre to dispose of Papa's and Dr. Koenigswald's bodies. During this process, the Hoenikkers share with Jonah the story of the night their father told them about ice-nine. He had been making the substance in saucepans all day, shifting the molecules and then melting the ice down again. When ice-nine is melted, it returns to the same harmless state as natural water. Felix decided to take a break before cleaning up and melting down the remnants of his experiments, but he died in his rocking chair before he could do so. The whole day he had been teasing his children with the idea of ice-nine, urging them to stretch their minds and telling them its essential properties to see if they could guess what it was. They later found their father dead. None of the three children can explain why they each took a piece of the ice-nine. For them it is not a matter of morality. It is a matter of fact. After cleaning and scheduling the funeral pyre, everyone heads to the ceremony in honor of the Hundred Martyrs.
At the ceremony, Horlick Minton makes a speech that portrays all people who die in war as murdered children. He argues that ceremonies such as the one they are all attending should focus on eliminating false celebrations of honor and patriotism. Horlick expresses his appreciation for a thrilling show, but he argues that the only way to justify such shows is to hold them in conjunction with real efforts to reduce the stupidity and viciousness of humankind. He tosses a wreath into the sea, and the San Lorenzan air force begins its mission to destroy the cardboard caricatures floating in the sea.
Unfortunately, one of the planes in the show catches fire and crashes into the rocks over Papa's castle. The castle begins to fall and crumble, and the chaos that follows claims the lives of the Mintons. In a few ground-moving, terrain-shaking moments, Papa's bed and body are swept into the sea. It does not take long for ice-nine to cover the world and set off a chain of ecological disasters that kill almost all of Earth's inhabitants. From that point on, tornadoes cover the skies like worms.
Jonah and Mona find an underground bomb shelter in Papa's oubliette, where they can survive for a while. During this time, Jonah realizes that his lust for Mona may be misplaced, seeing that their only attempt at sex is met with much sweating and frustration but not very much pleasure. Afterward, Mona expresses her disdain for the activity.
The tornadoes begin to subside, and Mona and Jonah decide to venture out of their hiding place to see what has happened to the rest of the world. At first they are amazed to see that there are no dead bodies scattered around the island, but then they find most of the old inhabitants on Mount McCabe. Each has lain down calmly and committed suicide with ice-nine at the suggestion of Bokonon. Mona laughs at Jonah's dismay at the San Lorenzans' fates. She asks Jonah if he would ever wish any of the poor San Lorenzans alive again. Then she kills herself with ice-nine.
H. Lowe, Hazel, and Newt find Jonah later, and though he does not remember, they say he was crying. They take him back to Frank's house, where they live for six months with most of the creature comforts they had known before. Because ice-nine has frozen all of the animals on the island, the survivors have a reliable food source that they can defrost whenever they are hungry. Water is made by melting pure ice-nine. Hazel spends her time sewing an American flag, H. Lowe works as their cook, Newt paints, and Frank spends his days playing with an ant farm he has created. Ants are the only animals that survive, because they figure out a way to melt ice-nine with their bodies to make water.
Frank builds a transmitter to send S.O.S. signals, while John writes the present novel. Frank believes that he has matured a great deal following the destruction of the world. He does not lack self-confidence as much, and he does not care about what others think of him. Jonah reminds him that he has also killed almost every living thing on Earth, and that there are far fewer people to be socially anxious around. Frank ignores his comment.
Newt and Jonah discuss their lost sex drives one day as they are driving the only taxi around the island, and they realize that sex is uninteresting now that the world is truly hopeless and not worth inhabiting. John spots Bokonon sitting on a rock writing the last of his religious books, and he stops to speak with the prophet. Bokonon's last book reveals that, if he were a younger man, he would write a history of humanity's stupidity. Then, he would lie on the ground and thumb his nose at God, right before committing suicide.
The Hoenikkers' tale of how they got their father's ice-nine highlights the disconnection between science and moral thinking. None of the children considered the questions of whether they should take the ice-nine or whether it was theirs to take, and this thoughtlessness exemplifies the relationship between science and morality in the novel. Discoveries are made without concern for their ultimate effect on humanity, and they are lauded by the world as advancements without regard to the moral and other human implications of making use of the discoveries. Most people do not understand the implications of scientists' research. Thus, the moral question is never asked, and science is permitted to exist in a vacuum.
Horlick Minton's speech is an attempt to make a small impact on people's perceptions of war and patriotism. The Hundred Martyrs' deaths seem unnecessary, but because they died in the name of democracy, they are now national heroes. Patriotism is unmasked as one of the world's worst granfalloons, because it is one for which people are most willing to die.
Papa Monzano's voyage to the sea in Bokonon's golden lifeboat fulfills Bokononist prophecy. However, because of the negligence of Jonah and the Hoenikkers, it can be argued on either side that the fulfillment of this prophecy is either destiny or the result of an abuse of free will. Perhaps the people subconsciously enable Bokonon's prophecy through their repeated mishandling of ice-nine.
In the final sections of Bokonon's work, Bokonon criticizes man's need for reason in his life. His version of God's whimsical creation of man and man's subsequent request for a purpose clearly indicates that he believes that man's search for reason is self-imposed. God tells man that he can have the privilege of making up a reason for life. Bokonon writes that man may be angry at this existence, but telling God of his anger would be pointless because God would only laugh. There is also no deep meaning behind the destruction of the Earth. It is the product of an accident by stupid humans. Since Earth's destruction is no more accidental than Earth's creation, it should not be considered a tragedy, but merely the result of a series of unimportant events.
Hazel's desire to create an American flag is a commentary on humanity's inability to learn from its mistakes. Since San Lorenzo's discovery, different nations have been claiming it mainly for the sake of doing so, or being mistaken about it having any real value. At the end of the Earth, with no one there to fight her for it, Hazel somehow remains interested in laying claim to this worthless land mass in the name of a now presumably nonexistent nation.
Newt and Jonah realize that the whole point of life might be the perpetuation of the human race through reproduction. They cannot think of any reason for existence other than existence itself. Thus, all of humanity's attempts to define and discover the meaning of life are nothing more than a cat's cradle, a funny-looking string that has not become a cat or a cradle.