Borne is about a woman named Rachel who is trying to survive in a post-apocalyptic city terrorized by a giant flying bear named Mord. The city is overrun by genetically engineered creatures called ‘biotech’ that was created by the Company, a corrupt organization that exploited the city for its resources. One day while scavenging, Rachel finds mysterious biotech caught in Mord’s fur. She brings the biotech home and names it Borne, becoming attached to it in a motherly way despite the protests of her partner, an outcast scientist named Wick. Rachel soon realizes that Borne is sentient and can speak, learn, and grow at an alarming rate. As Borne develops, he begins to question his role in the world and whether or not he is a ‘person’. As the story continues, Borne is unable to control his urges to absorb/kill other people and biotech. Rachel banishes him from her and Wick’s hideout for their protection, but cannot bring herself to kill Borne. 

Later, when their hideout is attacked, Rachel and Wick escape to the abandoned Company building. Inside, they find a one-way door to an unaffected city that was used to receive supplies. They discover that the Company had made the city dependent on them, experimented recklessly, and then fled when the biotech (Mord) became too dangerous. Rachel finds crates of dormant Borne pods that had been sent to destroy or cleanse the city of rogue biotech. They might have succeeded if someone hadn’t spiked and killed all but Borne. In the end, Borne becomes powerful enough to challenge Mord for control over the city. He absorbs Mord but is reduced to his dormant form after. With Mord dead and Borne in a plant-like state, the city slowly begins to recover and rebuild (VanderMeer).