William regularly runs the Hope between the Hawkesbury and Sydney, bringing the settlers' goods to market and returning with goods for them to purchase. In general, life is going well for the family. The Hope brings in regular money, Sal now has a fireplace in the hut, and the children are benefiting from the fresh air and warm weather, even Bub who was always so sickly. The settlements along the Hawkesbury have been joined by townships filled with garrisons of soldiers to protect the settlers from the 'outrages and depredations' of the Aborigines and encourage them not to abandon the land. As more settlers arrive in the area, the number of conflicts with the Aborigines rises.
One day in December 1813, William arrives home on the Hope to be met by Willie, who tells him breathlessly that the blacks have come. A clan of Aborigines have made a camp behind the Thornhill's clearing. Sal gives William a parcel of flour, pork, and tobacco to take to the Aborigines in an effort to bribe them to leave. William refuses to take the parcel because it reminds him of paying rent for their miserable little room in London. He shouldn't have to give the blacks anything. They were on his land, not the other way around. Sal compares the Aborigines to the gypsies back home. She says that it is best to give them a little but to not let them take advantage. Soon enough, they will be on their way. Both Sal and William understand that some sort of line has to be drawn in their interaction with the Aborigines. If they do not draw a line, then they will never be able to claim the land as their own.
William goes to the Aborigines' camp to tell them to move on. Two older women are tending the camp, naked except for a string around their waist. William is acutely embarrassed by their nakedness, but he is determined to get them to leave his land. William tells the women to go away, but they ignore him. One of the women speaks harshly to William and then turns her back on him, making William feel as if he is being dismissed. Annoyed at being treated in a high-handed way by a mere savage, William threatens to get his gun. The second of the two women says something to him and jerks her head, telling him to go away.
Suddenly, William feels a presence behind him. The men have returned, spears in their strong hands. William tries to speak to the men, but his words are met with silence. He grows increasingly nervous in the face of their silence and speaks to them in a patronizing tone. William uses a stick to draw a rough map of the land that he has claimed. He tries to explain that the section of land is now his, they can keep all the rest. The old man, who William met soon after their arrival at Thornhill's Point, seems to be the elder of the clan. He picks up a clump of the daisy-roots and eats one. He offers William one, but William refuses. The man points to the flat land near the river and then to the daisy roots. The man is trying to tell William that the daisy yams grow on the flats near the river where William is planting his crop. William senses that the man is asking him something. Unsure of the question he is answering, William nods his head in assent. The man seems satisfied, and William returns to his family. However, he does not know what he agreed to, and he longs to be able to communicate with the clan of Aborigines. He hopes for the best and tells Sal that the Aborigines will be on their way soon.
But the Aborigines stay on, and the smoke from the fire rising above the trees constantly reminds William of their presence. He begins to give them names, making them less threatening by pulling them into his world. He names the village elder Whisker Harry. The Aborigines go about their life as if the Thornhills do not exist. Sal deals with the presence of the Aboriginal women walking through her yard on a regular basis by pretending they are just like the women she knew back in London. Like William, she gives them familiar names - Polly and Meg. She chatters at them, jokingly asking how to stew rats and other animals. One day, a young woman touches Sal's skirt and shrieks. Sal looks at her and says, "Why you're no better than a dumb animal." Thinking of the Aborigines as dumb animals makes them seem less threatening. Sal trades her bonnet and a bit of sugar for one of their bowls, which she intends to take back to London and sell as a collector's piece to the gentry. While Sal makes fun of the Aboriginal women, they in turn make fun of Sal. William sees one of the women put the bonnet on her bottom, mocking Sal and her ridiculous clothes.
As the Aborigines stay on and on, William and Sal begin to worry that they will never leave. William turns Blackwood's advice - give a little, take a little - over and over in his mind, but he does not understand how to put it into practice. William decides to visit Blackwood and ask him how to get the Aborigines to move on. Blackwood does not welcome visitors, but he agrees to talk to William. Blackwood tells William about when the Aborigines confronted him about the settlement he was building on the river. He offered them food and his hat, but they ignored the gestures. The Aborigines made it clear that Blackwood should go no farther than the beach. He could stay, but only if he did not encroach on their territory. Blackwood tries to convey to William that the Aborigines were the ones with the power to decide whether or not he stayed. William seems to miss the point of the story, which is that it is not William's right to tell the Aborigines to leave his land. The Aborigines are the one who are letting him stay, not vice-versa. William finds little practical help in Blackwood's story.
As William gets up to leave, he sees an Aboriginal woman at the edge of the trees. She speaks angrily to Blackwood, who responds in her language. William recognizes the energy of a man and woman who live together. A child with light skin and straw-coloured hair appears at her side. William understands with a shock that Blackwood must have had a child with the woman. Blackwood warns William not to tell anyone about the woman and the child or he'll kill him.
William's second son, Dick, loves the nature around Thornhill's Point. As soon as he finishes his chores, he disappears to explore the river and the forest. Dick also plays with the Aboriginal children, swimming naked in the river. When Sal finds out that Dick is swimming naked like the savages, she sends William to bring him home. William finds Dick clustered around the young Aboriginal man who confronted William when they first arrived at Thornhill's Point. The man is showing the children how to start a fire by rubbing two sticks together. William is amazed to see the first spark of fire. The man looks at William with a challenge in his eyes. He knows that William would never be able to start a fire without a flint or a match.
Impressed with the man's skill and trying to put Dick at ease, William points to himself and says, Me, Thornhill. The Aborigine quickly catches on and points to himself, saying a string of sounds. William catches something that sounds to his ears like Jack. From then on, the Aborigine is known as Long Jack. William appreciates Long Jack's strong physique and skills, and it is almost with regret that he tells Long Jack that the Aborigines’ time on the land is coming to an end. William remembers the streets of London teeming with people, and the unending boatloads of convicts arriving in Sydney. He says that there won't be any way to stop the white settlers from taking over the land, "There's such a bleeding lot of us."
William tries to explain to Dick that he can't run around with no clothes on and play with savages. But Dick is a strong-willed child, and he has come to appreciate the Aborigines. He doesn't think they are savages. He tells his father that they can do a lot more than he can, and they don't have to spend all day tending the corn. William is furious, and he gives Dick a beating. He takes out his frustration at the Aborigines on Dick. Afterwards, Sal makes William realize that the nature surrounding Thornhill's Point is Dick's playground, just as Rotherhithe was theirs when they were children. William feels bad for beating Dick and knows that he has hurt the boy emotionally as well as physically. Dick refuses to sever contact with the Aborigines, and the next day William finds him in the forest trying to start a fire with two sticks. Looking for a way to make up with Dick, William offers to help him. They do not manage to start a fire, but their experiment reduces the rift between them. William tells Dick to have Long Jack show him again, giving the boy tacit permission to continue to spend time with the Aborigines.
One day in January, William notices plume of smoke coming from near the Aborigines' camp. They have started a fire along the slope. The Aborigines control the fire with branches of leaves. William and the others think that the Aborigines started the fire just to catch the lizards running away from the flame. They think the Aborigines are lazy and wasteful, burning a whole patch of land just to catch a few lizards. But they soon realize that the Aborigines have a long term plan for the burned land. Soon, new shoots of grass appear, attracting whole families of kangaroos. The Aborigines pick off the kangaroos when they come to feed. The smell of fresh meat cooking drifts over to the Thornhills' camp, making their mouths water. William decides to shoot a kangaroo for their own pot. But he is not an experienced hunter, and the kangaroos easily avoid him.
William approaches the Aborigines with the hope of trading flour for some kangaroo meat. Whisker Harry accepts the flour and gives William a leg of kangaroo. The meat is still covered in hair, and William cannot get figure out how to skin it. He finally takes an axe to it, cutting it up into pieces. The poor butchering leaves little to roast, so Sal makes a soup with the meat. They have to strain the liquid through muslin to catch the hairs William could not remove. While the soup is satisfying, it does not come close to taste of roasted meat.
On one of his regular trips into Sydney, William stops at Smasher Sullivan's place. Smasher's place is filled with empty oyster shells. The abundance of oysters that William saw when on his first trip up the Hawkesbury is disappearing. Smasher says the blacks have moved out of the area because there's nothing left to eat. A Aboriginal man suddenly appears on the bank of the river, an oyster in his hand. He gestures toward the pile of steaming oysters on Smasher's fire and then opens his own oyster and eats it. He points to Smasher's oysters and then down to the bare rock where they used to live. The Aborigine is pointing out that the oyster supplies are running low because of overconsumption. Smasher cracks his long whip into the dust beside the man. When he doesn't move, Smasher whips him across the chest. The man catches the end of the whip and glares at Smasher. Then he lets go and returns to his canoe. Smasher tries to shoot him, but he cannot get the gun loaded in time.
Smasher turns on William, accusing him of cozying up to the blacks. He says he knows what Blackwood's up to with that woman. Concerned that Blackwood's secret is well known along the river, William loads the last of Smasher's kegs onto the boat and leaves.
In A Hundred Acres, Grenville develops the theme of the clash of civilizations. When the clan of Aborigines set up camp on Thornhill's Point, William and Sal are forced to confront the reality of their presence. Previously, William and Sal did not discuss the Aborigines living in the forests surrounding them. The Aborigines were a shadowy presence that they chose to ignore, hoping they would go away. Infected with the fear that Smasher Sullivan spreads with his stories of roasted babies, William assumes that the Aborigines have come to harm his family. He is surprised to see their peaceful little camp. This chapter explores the tension that exists between two peoples living on the same land and charts William's increasing understanding of the Aborigines and their culture. The chapter also sets up the denouement of the novel, when William must choose between learning to live with the Aborigines and fully claiming the land as his own.
William's first visit to the camp ends in a silent agreement with the Whisker Harry. Although William threatens to shoot the Aborigines, he is essentially a humane individual. He does not want to hurt the Aborigines, he just wants them to go away and leave him with his dream intact. William understands that the clan has made a camp at Thornhill's Point because the daisy yams grow there. Trying to follow Blackwood's advice of give a little and take a little, William lets them stay with the hope that they will soon move on.
However, the Aborigines stay and stay. William and Sal must interact with them on a regular basis. Their nakedness and casual way of life irk and embarrass William and Sal. Just as Sal carved a yard out of the wilderness to create the sense of something familiar, so William and Sal give ordinary names to the Aborigines, trying to bridge the abyss between the two cultures. Sal chats with the Aboriginal women as they pass by the hut just as she would chat with her neighbors in London. However, her patter is laced with racist comments and the assumption that the women are little more than animals. Grenville undermines Sal's sense of racial and civilizational superiority in the episode with the bonnet. While Sal laughs at the women for the incongruity of the bonnet next to their primal nakedness, the Aborigine women see Sal's clothes as absurd. One woman puts the bonnet on her bottom, demonstrating a marked lack of respect for the trappings of white culture.
Grenville introduces William to Aboriginal culture through the intermediary of a child who has yet to fully absorb the racial prejudice of his society. William's son Dick loves to explore the natural beauty of Thornhill's Point. During his many excursions, he encounters the Aborigines and begins to play with their children. Dick is an inherently curious child, and he becomes fascinated with the way the Aborigines live alongside nature and the impressive skills they possess. Dick's interest in the Aborigines opens William's eyes to the fact that the Aborigines are not savages. William is thoroughly impressed with Long Jack's ability to start a fire with two sticks, and the reason he gets so angry at Dick for saying that the Aborigines know how to live better because they don't spend all day sweating over a patch of corn is that he senses an element of truth in the statement. If the Aboriginal way of life has something to offer, then the value of everything that William desires, such as social prestige and power, and everything that he works hard for, the domination and ownership of the land, is undermined.
William grows to grudgingly appreciate the Aborigines' skills and their way of life. When he watches the Aborigines burn the land, he thinks it is just a lazy way to drive lizards out into the open. However, when the kangaroos start to appear, William suddenly realizes the simple beauty of the technique. For the first time, he sees the Aborigines as more than savages.
However, he resents the ease with which the Aborigines live their lives. The incident in which the Aborigines burn the grass to attract kangaroos makes William feel inferior, a feeling he wants to leave behind forever. Each time he watches an Aborigine carry home a dead kangaroo, he remembers his failed attempt to shoot one. Each time the smell of cooking meat drifts over the hut, he resents their presence on his land, showing him up in front of his family and servants who have only old pork and cornbread to eat. He resents having to ask for a piece of meat that was caught on his land. The role reversal - a white settler approaching an Aborigine for food - leaves a bitter taste in his mouth. William wants to become the new gentry of Australia, and he can't achieve that dream while living side by side with the Aborigines.
This tension between the white settlers' desires and the Aboriginal way of life appears again at the end of the chapter in the scene at Smasher Sullivan's place. The settlers do not want to be told by a naked man holding a spear that their way of life is harming the natural environment. Like Smasher, they don't want limits placed on their desires.. While the Aborigines believe in preserving the natural balance, the white settler believes that nature exists to serve them.