Gabi and Winston, two employees of South Africa's forestry service, are travelling along a river in the Tsitsikamma forest[3] when Gabi loses the drone she is controlling. Gabi decides to enter the forest, retrieve the drone and rejoin Winston later, saying: "we can't just leave our trash here."While walking through the forest, Gabi triggers a trap, which leads to a wooden stake piercing through her foot. Gabi removes the stake and heads deeper into the forest, which is soon covered by a red glow as night falls. She comes across a wooden house, and enters it to rest and recover from her injury. Barend and his son Stefan, two survivalists who had set up the trap and who live in the house, find Gabi resting in the house and treat her injury.Winston hears Gabi scream as she pulls out the stake, and he heads into the forest to look for her, but is unable to find her. After night falls, he encounters strange creatures in the forest, and becomes infected by a rapidly-growing fungus while hiding from the creatures.Throughout the film, Gabi grows close to Stefan, and she also experiences nightmares that involve fungi growing from her body, later finding patches of fungi growing on her arms and legs. She learns from Barend that he used to be a plant pathologist who started living in the forest after his wife Lily died of bone cancer thirteen years prior, and that Stefan was conceived in the house, which was where he and Lily had their honeymoon. Barend then states that he met "God" while in the forest.Later, Gabi is almost infected by a similar rapidly-growing fungus while sleeping, but she is saved when Barend wakes her up due to the creatures trying to break into the house. The creatures break in, and are revealed to be ordinary humans covered with fungus. Barend explains that the fungus infects humans and feeds on the eyes, mouth and lungs, and that they infect other people via spores. He also explains that the largest organism on the planet lives close to the house and is looking to spread, saying: "She was here long before the apes started dreaming of gods."The next day, Gabi finds Barend's writings, which compare humanity to monkeys in captivity. Barend provides offerings to a tree, which contains the previously-mentioned organism, and both he and Stefan eat some of the mushrooms growing in the tree. Barend and Gabi start heading out of the forest when Gabi finds Winston's flashlight, and they find Winston, who is now covered with several species of fungi. Winston, who is still alive, begs them to kill him. Gabi stops Barend from shooting him with an arrow. Barend then places an arrow in front of Winston's mouth which he impales himself on it. The noise attracts the attention of the creatures, forcing Barend and Gabi to return to the house.After finding lichen on her thigh, Stefan secretly gives Gabi one of the mushrooms that Barend has been harvesting from the offering tree.Stefan takes Gabi to see his mother, who has been transformed into an animate tree, and still has her wedding ring on one of her transformed fingers. Gabi goes through the photos stored in an SD card from one of the cameras she and Winston placed in the forest, and finds that several of the photos show the creatures. Barend reveals in a rant that he believes the world is doomed due to humanity's actions.Gabi and Stefan begin heading towards the city, but are confronted by Barend, who convinces Stefan to stay in the forest. Gabi begins heading back to the city alone, and Barend decides to sacrifice Stefan to the organism. However, Gabi changes her mind, and she returns in time to stop Barend from sacrificing Stefan; Stefan ends up stabbing Barend in the spine during their struggle. Barend is later shown with the fungus growing from his back and offering his own blood to the organism.Some time later, Gabi becomes infected by the fungus, and her body becomes covered with it. She begs Stefan to kill her, and it is implied that he does so. Stefan leaves Gabi's body in the house and heads to the city, where he has a meal and then leaves the restaurant; the leftovers of his meal quickly become covered with fungus. (thanks to Wikipedia)