Zoe
Ryder's realization that the little zombie crying in front of him reminded him of his past, a time when he would cry because of an injury or when he was being bullied by other kids. He was about to attack the little zombie, but he stopped when he saw her crying. Ryder was surprised to find out that this was the second zombie he had come across who could speak. The little zombie introduced herself as Zoe.
Zoe revealed that she had evolved after drinking Ryder's blood and had become a mutant. She asked Ryder why he hated zombies so much, and he briefly explained his story after the apocalypse and how he had become a zombie hunter. Zoe was moved to tears by Ryder's story, and she began to tell him about her life before she became a zombie.
Zoe told Ryder that she was only six years old when her parents got divorced because she had cancer. Her mother couldn't bear the burden of having a child with skin cancer, and so she left them. Her father took custody of her and tried his best to make her happy and forget about all the bad things so that she could leave the world in peace. It had been two years since her father took custody of her, and then he died in a car accident. Zoe was now an orphan because her mother committed suicide two months after divorcing her husband.
Zoe was still in the hospital for one more year because of the charity she was receiving from other people. Unfortunately, during the outbreak of the NEBULA virus, Zoe became infected because she didn't have immunity to airborne NEBULA and turned into a mutant zombie. As mutant zombies have instincts just like animals, she ran away from the city to avoid people who owned guns and the army.
After a few days of running, she arrived at an old village where there were no signs of life besides Ryder. And that's how she ended up there and evolved. Ryder was touched by Zoe's story and felt sympathy for her, realizing that not all zombies are evil. However, as Ryder was lost in thought, he swung his fist in reaction to a zombie near his bed, endangering Zoe.