Ian Smith and Samantha "Sam" Shaw are a couple taking a romantic New Year's Eve trip in the outback. They head to remote beaches for weekends away from the stress of city life. On the way, they met the German, a man who suggested they camp on the beach near the waterfall. When they arrived, they set up camp near an abandoned campground with no trace of its occupants. Sam suggests to Ian that they should get married, and Ian happily agrees.
For a few nights, they get worried when they find out about their traumatized baby. Elsewhere, the German told his colleague Chook about Ian and Sam, and the two began making plans. Chook was so excited to "go hunting" that he left without Germany that morning. Chook finds Ian and Sam with their baby, Ollie, stranded at the campsite when a tire blows out.
The Baker family - Robert, Margaret, their 16-year-old daughter Emily and their youngest son Ollie - had been camping in the same place three days earlier. The Germans and Chuck show up at the campsite and kidnap Robert, Margaret and Emily, unaware of Ollie's existence. The Germans and Chuck raped Margaret and Emily and tortured the family before murdering them. After finding Ollie in a photo on Emily's phone, they returned to look for him, but he was gone.
Back in the present, Chook convinces Ian to find the missing family. However, he intends to take Ian to Killing Ground to mock him with a corpse as part of a sick game. When they arrived, they found that Margaret had not been injured and had crawled to the creek. Ian tried to save her, but Chuk shot and killed her on the spot. When Chook explained his intention to rape Sam and kill him, Ian charged forward and knocked him down. But instead of fighting Chook, Ian ran away in a panic when Chook chased him.
Meanwhile, the Germans arrive at the camp to find Sam with Ollie. The Germans tried to kidnap Sam from the car, but she put her hand over her wrist and fled into the woods with Ollie. Germany frees his dog Banjo to attack them. However, Banjo was distracted by a wild boar, leaving the Germans to chase them.
Chook mistakenly shoots the German, thinking he is Ian. Chook apologised to the German as Ian watched from a hiding place. Nearby, Ollie begins to cry, relinquishing Sam and Ollie's place. Ian tried to retrieve the German snipping rifle , but he was too scared and went back to his hiding place. Chook killed the German, and he begged him to end his suffering. Chook grabs Sam's Ollie before throwing him to the ground. Chook then holds Sam hostage and tells Ian that he will be waiting at the killing site.
After Chook leaves Sam, Ian stops hiding and notices the German's car keys sticking out of his pocket. Meanwhile, Chook gets impatient with Ian not coming to save Sam, so he threatens to rape her. That's when he heard Ian running away in a truck in Germany. When Chook tries to intercept Ian, Chook angrily drags Sam away. As they passed the German's body, Sam noticed that Ollie was missing. Once in Chook's car, he insults Ian for abandoning Sam, but Sam believes Ian is with him with Ollie. Sam tries to fight Chook, causing him to crash into a tree, knocking them all unconscious. As night fell, Ian arrived at the police station and asked for help. He accompanied two officers to the campsite. Sam wakes up in the wreckage of the car, hands tied to the steering wheel, and Chook is not there. Police found the wreckage when Sam flashed head beams in the car, but Chook killed them as they exited the police car. Chook shoots Ian in the arm and holds him hostage. He asked Sam to drive him to a safe place. Sam complied and ran to save Ian from bleeding to death.
Sam asks Ian if Ollie survives, but Ian tells her that Ollie was never with him because he didn't know what to do and he ran to the police station. While Banjo quietly guarded him, Ollie was shown to be away from the German's corpse. His ultimate fate remains unknown.
While driving out of the camp, Sam decided to stop Chook and slammed the vehicle. Ian lost consciousness while Chuk - seriously injured - managed to get out of the wreckage. Sam and Chook argue with his pistol before smashing his head with a massive rock, which ends up killing him.
Eventually, Sam wakes up in a hospital, leaves her room, and finds Ian, recovering from a broken arm in another room. Sam stood silently by his bed, sad and disappointed.
