A week after the attack on the Webbs, William sails by Darkey Creek, an area with an Aboriginal camp. William first notices the silence. He pulls in the boat to investigate. The camp is deserted, except for dead bodies, whose mouths are encrusted with vomit. He discovers a boy around Dick's age still alive among the corpses. The boy is on the verge of death, vomiting and groaning on the ground. William brings the boy a drink of water, but the boys throws the water back up immediately. Green slime drips out of the boy's mouth. Shocked, William realizes that Saggity has gone ahead with his plan to poison the Aborigines with 'the green powder.' William does not know how to help the boy. He can no longer stand the carnage and leaves the boy to die.
The next morning, life at Thornhill's Point changes forever. Dick runs up the hut, shouting that the the blacks are picking all the corn. All of the tension of the previous months comes to a head. William grabs his gun and heads down to the corn patch. The Aborigines do not stop picking the corn as William approaches. The fact that they ignore him, the rightful owner of the corn, enrages William. He grabs one of the women by the hair and yells at them to go away. Another woman jumps on William and hits him on the head with her club. He drops the gun. A third woman attacks William, and he eventually fights them off. It looks like one of the woman has a broken arm.
Ned and Dan run down to the patch, guns in hand. Long Jack and Black Dick advance on William, but he turns the gun on them, yelling at them to leave their food alone. The Aborigines retreat, dragging the wounded woman behind them. Willie urges him to shoot them, but William hesitates. At the edge of the forest, Long Jack turns and stares at William, as if daring him to use the gun. William closes his eyes and fires the gun. When the smoke clears, Long Jack has disappeared. Dan caught a young boy around 12 years old and clubbed him over the head. Dan suggests they tie the boy up and use him as bait. When the others return, they can kill them all. But William takes pity on the boy and tells Ned to release him. William assures his family that the Aborigines have learned their lesson and won't return.
William awakes the next morning to find that the Aborigines have torched the corn patch. William takes the loss of the corn patch like a physical blow. The first thing he did when he arrived at Thornhill's Point was plant that corn patch. He feels as if everything he has worked for has been taken away from him. Sal stares at the burnt patch and then walks up towards the Aborigine's camp. She looks around her in silence, at the tidy shelters and the ringed fireplace. Sal realizes that the camp was their home, just like their home in London. It wasn't a make-shift stopping point, but a real home. She understands that the Aborigines have always lived on the land and that they will always return. William refuses to admit defeat, but Sal has given up. He tries to convince Sal to stay, but she is determined to take the children and leave - with or without William.
Before Sal can enforce her decision, William sees smoke at Saggity's place and leaves on the Hope with Ned and Dan to go help. They arrive too late. Saggity is lying on his back, a spear through his stomach. When Saggity continues to draw painful and futile breaths, William decides that he must take him on the boat up to Windsor. On the trip up to Windsor, William realizes that Sal will never agree to stay at Thornhill's Point after hearing about what happened to Saggity. He would have to set up house in Windsor or Sydney and one day return to London, abandoning his dream forever.
Saggity dies when someone finally pulls out the spear in Windsor. The entire township hears his dying scream. Smasher arrives in Windsor and begins riling up the other settlers, demanding a violent retribution for Saggity's murder. The men are drinking, their rage growing by the minute. William sits silently in the middle of the burgeoning mob. Smasher says there is a whole camp of Aborigines up at Blackwood's place. He says they should sail up that night and settle the problem once and for all by morning. The men need William's boat to take them up to Blackwood's place. William does not relish the thought of a slaughter, but Ned's insidious voice whispers in his ear, "Ain't no other way to hold her." (p.298) William knows that if the Aborigines remain, Sal will leave. William agrees.
They pick up more men from the settlement on the upper part of the river and arrive at the Aborigines' camp at dawn. The guns erupt. Women and children run for the cover of the trees but they are shot in the back and the children's throats cut. William stands with his gun at the ready but does not shoot. The carnage unfolds before him in slow motion. Then the Aborigine men enter the fray, throwing their deadly spears. Thomas Blackwood runs into the camp, shouting at them to stop. But Smasher whips him in the face, and Blackwood drops his gun. The Aborigines begin throwing large stones from the safety of the forest. Whisker Harry appears at the edge of the forest and launches his spear. it pierces Smasher's chest. Whisker Harry just stares at the dying Smasher, refusing to take cover in the trees. William lifts his gun and shoots Whisker Harry in the stomach.
William drops his gun. The battle is over, the land littered with the bodies of Aborigines and settlers. Dan walks over to a baby whose crying is disturbing the growing silence and clubs it to death. The men lift Smasher up and move him into the shed. Blood curdles out of his mouth and nose. He slumps over the spear and dies.
In The Secret River, Grenville sets the conflicting visions of the future development of Australian society on a collision course: Smasher Sullivan's domination and dispersal and Thomas Blackwood's peaceful co-existence. Throughout the novel, William is caught in the middle of these two approaches. William is a humane and generally non-violent man, who is disgusted by Smasher's murder and sexual abuse of the Aborigines. He is moved by pity when he finds the Aboriginal boy slowly dying from Saggity's poison. William is not blinded to the Aborigines' humanity. He sees the dying boy as a once-beloved son, like his own children. William wants to live according to Blackwood's advice, but he cannot figure out how to reconcile the presence of the Aborigines with his burning desire to claim full ownership over the land and become a member of the gentry of New South Wales.
When the clan of Aborigines living on Thornhill's Point begins to strip his crop of corn in violation of the very essence of the Western concept of ownership, William takes the first step on the road to the massacre at the end of the chapter. It is the Aborigines' defiance of his authority that enrages William and pushes him to his first act of violence in the novel. William has worked hard to earn the authority that he could not even dream of possessing as a young man in London. When the Aborigines refuse to recognize that hard-won authority, William feels as impotent as he did when the gentleman in London flaunted his wife in William's face. As a poor waterman in London, William could do nothing but accept behavior meant to degrade and humiliate him. But as a landowner in New South Wales, William has a gun and the laws of the British Empire to support his right to use it. The shot he fires at Long Jack sends an addictive thrill of power through William. Now that he has a taste of power, William will not give it up.
Sal's insistence on leaving Thornhill's Point after the Aborigines burn their corn patch pushes William to a point of no return. When Sal views the Aborigines' camp, she correctly understands that the land is their home. While this is not a new theme or observation in the novel, the full realization of that fact tears away the veil of self-delusion William had adopted since he decided to claim Thornhill's Point. William refuses to relinquish his dream of becoming a member of the new gentry - his entire sense of self is bound up in that dream. Although William is not yet ready to consciously recognize it, he now knows that if the Aborigines will not leave of their own accord, he will have to make them leave.
When William finds Saggity with a spear through his stomach, William foresees the inevitable end to the 'native problem.' However, the good man inside him is still unwilling to take the final step. He wills Saggity to die so that he does not have to take him into Windsor and set his foot on a path of no return. With Saggity's death, Smasher Sullivan's new Australia becomes a reality. William sits quietly in the midst of the ranting men because his motivation is not anger but desperation. He sits drinking rum, feeling his back pushed farther and farther against the wall. In this scene, Ned symbolizes William's unconscious decision to step over the line. His whisper in William's ear is the whisper of William's unconscious mind. The idea of participating in a slaughter is so horrific to William's conscious mind that it can only be conveyed in a whisper.
William watches the massacre as if in slow motion. The two symbols of Australia's future, Smasher Sullivan and Thomas Blackwood, square off among the dead and dying. Blackwood's humane path is violently cut down by Smasher's whip. Although Smasher himself dies by the spear, the massacre itself represents the final victory of his philosophy of domination. William plays the lead role in the symbolic end to Aboriginal life in New South Wales. He shoots Whisker Harry, cutting off the head of the Aboriginal hydra.