In a world overtaken by a virus that turns people into zombies within 48 hours, husband and wife, Andy and Kay, and their one year old daughter, Rosie, are living safely on a houseboat in rural Australia.While relocating for the night, Andy spots two children playing on the shore of the river. He shouts out to them, but continues the cruise after the father, noticing Andy, flashes a revolver in his belt. Later that day, Andy is using a net to fish supplies out of the water. Kay mentions their food rations are starting to run out, but Andy debates her plans to go on land. The scene changes to one of a young Aboriginal girl attaching leaves to her shoes. It goes back to Andy after a minute, who has spotted an abandoned sailboat, proceeding to investigate it. He retrieves food, and presents it to a skeptical Kay.After reassuring her the sailboat he ransacked was safe, Kay decides to return by herself to try and collect more supplies. Andy had previously left when he heard thuds coming from a door in the wall, but Kay, unaware of this, is presumably attacked by a zombie that emerges from the door.Andy awakens to Rosie crying, and goes in search of Kay. She is in the bathroom of the houseboat, trying to restrain the bloodflow from a bite on her knee. She is next seen investigating a pack that was previously acquired by Andy from the river. In it is contained a bracelet that measures the amount of time left for an infected, which Kay puts on, and an injection that neutralizes the brain, so an infected feels no pain whilst transitioning. Andy and Kay discuss their plans, confirming her vulnerability. The family decides to abandon the houseboat and venture to a hospital. They pass by the burning remnants of a body.Thoomi, the Aboriginal girl, is drawing in a sketchbook. She leaves behind the picture of a man with his head in the ground, then leaves her shelter with a rabbit carcass, which she throws into a pit. Gargling is heard and she covers her ears.Andy and Kay have found a vehicle. While Andy fills the gas tank, Kay notices a yellow slime on the seat back. They narrowly evade a zombie trudging towards them. As they drive away, one is seen struggling to lift its head from the ground. They stop on a deserted stretch of road so Andy can look at a map, and Kay change Rosie's diaper. She collapses offscreen, convulsing and throwing up blood while Andy holds her steady.Thoomi is seen once more throwing a snake carcass into the pit, but no sounds are heard. She climbs down to check, and then exits hastily.Kay comes to her senses and checks her wound in the car to see it is oozing yellow slime. In a fit she exits the car and has a shouting match with Andy, angered he has been trying to keep her developments from her. He subdues her and convinces her to continue with him. Andy breaks the door handle to keep Kay from trying to escape again. On the road, Andy is distracted by a lone man and consequentially crashes the car into a tree, impaling Kay. Andy faints from shock, leaving Rosie strapped in her seat. He comes to hours later and tries to wake Kay, but realizes she has already converted, as evidenced by pus around her eyes and mouth. He is bitten by her while trying to exit the car. Following this, Andy approaches the car, Rosie sitting a distance away safely, and uses one of the injections on Kay. He takes her bracelet and places it on himself instead, then begins travelling on foot with Rosie on his back. She cries for a great part of the journey, until he uses Kay's perfume to calm her. While resting, he spots the man that had caused their crash, but realizing he is a zombie, prepares to defend himself. Thoomi appears to dissuade Andy from hurting the man, her father, and cuts her hand with a rock to draw blood and lead him away.Andy arrives at the town he intended to reach, entering a school and meeting Etta, a retired teacher. She helps him clean his wounds, and informs him that all the Aboriginal people have left the land, including many of her former students. Andy steps outside and sees fires in the distance, started by the Aboriginals. A woman is seen calling for Thoomi. That night, in a hospital room, Andy has his first seizure. He awakens the next morning, going outside to meet Etta, who tells him to seek a man named Willie, Thoomi's father, to take care of Rosie. She explains the purpose of the fires, started by Aboriginal hunting parties that are cleansing the land by killing zombies they encounter. Etta warns Andy to stay out of their range. On his journey Andy stops at some ruins to give Rosie water. He passes several zombies with their heads in the ground, hastily leaving the area, but one rises and proceeds to follow him. He finds a truck and attempts to hijack it, but is stopped by a man named Vic, who saves Andy from the zombie that had been after him, of which Andy was unaware. Vic is trapped under a tank and gives Andy the keys, making him promise to rescue him first, and then they can escape approaching zombies together. Vic takes Andy to his shelter, an outpost formerly part of a gas plant. He meets Vic's wife, Lorraine, who is quietly surprised to see other "people who are still people". Vic encourages Andy to leave Rosie with Lorraine so the two men can go to work. Work is shooting groups of zombies and collecting their valuables, as Vic believes when the country returns to normal people will want riches again. Vic attracts the zombies by imprisoning live, healthy humans inside cages as bait. Andy is perturbed to see Thoomi trapped. At the shelter, Lorraine is taking care of Rosie. As the power goes out, Rosie becomes uncomfortable. Lorraine attempts to cheer her up, but discovers slime on her stomach.Vic visits another cage with Andy. He uses entrails, a radio, and blood to lure zombies, all factors which make Andy question himself for a moment. The men return to the shelter, where Lorraine briefly mentions cleaning up Rosie. Andy plays with his daughter before setting her down in a makeshift crib, his hand starting to spasm. He leaves the shelter with an injection, but cannot bring himself to use it. Lorraine comes upon him, confessing she is not Vic's wife, and that Vic let her husband die along with other gas plant workers to save himself. Vic approaches them and knocks Andy out with the butt of his rifle out of suspicion, the latter awakening chained in the same cage as Thoomi. They agree to help each other escape by using the combined force of many zombies to open their cage, returning successfully to the shelter, rescuing Lorraine, Rosie, and the keys to both cages and chains. They don't get very far before Vic emerges from the shelter and shoots at them. Lorraine sacrifices herself for them to escape.Thoomi leads Andy to the cage he visited earlier, but the man inside is gone. They evade Vic tracking them down, and spend the night in a small gulch. After releasing each other of their chain, they are presumed to fall asleep, until later in the night Thoomi wakes up to heavy breathing and hides with Rosie while Andy rubs his face against blood on the wall. The following morning Andy and Thoomi have a conversation about her father's health, which results in Thoomi running off after Andy asserts her father will not get better. The same woman who has been seen calling for Thoomi leaves Willie's jacket on a tree limb. Thoomi arrives to see her father has been straddled atop the tree, dead. Andy arrives to comfort her, but leaves promptly when he cannot console Thoomi. He has another breakdown and begins to try and burrow his head into the ground. Thoomi remains at the tree grieving, but is able to hear Rosie's cry and goes to retrieve her. Andy is confronted by Thoomi after he rouses, who has decided to help him reach the river.They travel by motorboat to the campsite where Andy last saw the family, inspecting the RV in which the family was staying. Andy leaves with Rosie to go find the family, while Thoomi stays in the RV. He meets the father, who has been bitten, and once again shows him his revolver. The father says it contains six bullets, and that Andy can have the remaining two once he uses them on himself and his family. Andy retreats as three gunshots are heard in the distance. The fourth is delayed while the father follows Andy, using it on himself and collapsing behind him. Andy collects the gun as intended and debates whether to shoot himself as well. Thoomi rushes to them, having removed her leaves and claiming she is ready to go home. They set off together towards the sight of smoke on a nearby hill.As they pass through a train tunnel, they encounter Vic. Thoomi hides with Rosie inside a parked vehicle on the tracks, while Andy tries to distract Vic. The two men fight, and Andy shoots the bullets, but misses both times. Andy, briefly defeated, is unable to help Thoomi, who Vic pulls from the car, in the process hitting her head on the rails. She lies in pain, Vic grabbing hold of Rosie. Andy rises to check on Thoomi, who is still alive, and then Rosie, who Vic is cradling, lamenting the incidental death of Lorraine. He tearfully hands over Rosie so that Andy can renew his walk with a hurt Thoomi.On the way Andy has another lapse, almost indulging in decayed meat. With little time left, Andy asks of Thoomi to promise to look after Rosie, with whom Andy shares a farewell before preparing himself for the finalization by placing a guard in his mouth, binding his wrists, and wrapping the meat from earlier on a stick. He then succumbs, his eyes crusted over.The Aboriginal warriors have finished their raid, but Thoomi calls out to them with a whistle, drawing attention of the woman, her mother. Thoomi and Rosie are riding Andy, who is guided by the meat on the stick, and being perfectly harmless is detained by the warriors while Thoomi and Rosie are welcomed back by her mother. One of the warriors attempts to strike Andy with his spear, but Thoomi stops him. She takes out Kay's perfume bottle, and sprays it one last time, the smell pacifying Andy, for a moment returning his consciousness as he realizes Rosie is finally safe. Thoomi then allows the warrior to put Andy out of his misery.The Aboriginal people are seen traveling to a refuge of many of their people where they are welcomed heartily. As Thoomi and her mother inspect Rosie, the words Thank You are read on her stomach, written in white paint which Thoomi and the warriors have used to disguise their scent from the zombies. The final shots of the movie are of Andy's plaid shirt and Rosie's fishing bait mobile hung on a tree.