Many people have moved into the community recently. In addition to Ms. Liu's family, two other families have moved into this building: a young couple on the 8th floor and a middle-aged couple and their children on the 1st floor. Are these people related to Ms. Liu? Thinking about it carefully, although their behavior in the surveillance footage doesn't seem abnormal, the layout of their residences is very coincidental. There are many people living at the entrance and back of the community, as if they are specifically guarding it. Moreover, there are people living on the first floor of each building, as if they are preventing people from escaping.

Xu Anran wasn't sure if she was being paranoid, but her intuition told her that three families in her building were watching her: Sister Liu, who lived nearby; the doorman on the first floor; and someone upstairs, trapping her with no way to escape. This feeling had grown stronger lately. Although she didn't know who Sister Liu and the others were, Xu Anran thought she should trust her intuition and leave quickly; being alone was the safest thing for her.

In the afternoon, while Xu Anran was exercising, Sister Liu knocked on the door again. This time, she came with her son: "Xiao Xu, are you there?" Xu Anran opened the door and asked what was wrong. Sister Liu said, "My son Xiaohao is doing his homework today, and he doesn't understand a few math problems. I thought since you're home today, I'd like to come and ask him." Xu Anran politely declined: "Sister Liu, the house is a bit messy right now, it's not convenient." Sister Liu seemed not to understand her refusal: "It's okay, I'll help you tidy up, and you can explain the problems to Xiaohao." Before Xu Anran could react, Sister Liu pulled the child and squeezed in from outside the door.

Seeing that the person had already entered, Xu Anran had no choice but to close the door and go inside. As she turned around, she felt a tremendous force that knocked her to the ground.

With the child pinning her down and choking her neck, Xu Anran struggled violently. She took out the stun gun she usually carried on her back, turned it on, and smashed it hard against the child's head. The child leaned back to dodge, and Xu Anran took the opportunity to bend over forcefully, throwing the child off her and standing up herself.

"Clap clap clap..." Sister Liu clapped her hands and said, "Impressive! Looks like your uncle was killed with the stun gun you're holding." Xu Anran didn't speak, but just leaned against the wall, holding the stun gun and staring intently at them. The child said impatiently, "Stop talking nonsense, hurry up and finish her off." Sister Liu didn't move, but leisurely walked to the dining table, poured a glass of water, took a sip, and said, "Don't be so boring. How about we play a game? You two fight, I won't participate." Then she pointed at Xu Anran, "If you win, we'll let you go, and we'll tell you anything you want to ask or want to know. But if you lose, then you'll die."

The child seemed dissatisfied with the suggestion, saying, "Why bother with all this fancy stuff?" Sister Liu stared at him intently and said, "What? You're not confident you'll win? You think you'll lose?" The child didn't say anything more, seemingly agreeing with Sister Liu's request. He turned to look at Xu Anran and sneered.

Then, the monster peeled off its skin, revealing a creature about 1.7 meters tall, roughly the same height as Xu Anran. It charged at her, kicking at the stun gun in her hand. Xu Anran's training had paid off; she quickly crouched down, striking the monster's shin with the stun gun in her left hand, and then pulled another stun gun from her trouser leg with her other hand. The monster fell forward after being injured, but Xu Anran quickly dodged. The monster rolled away, creating distance between them. Then, the monster crouched down and attacked Xu Anran's legs. Xu Anran lunged forward, aiming both stun guns at the monster's eyes.

The monster screamed in agony, but Xu Anran didn't let go. She kept stabbing the monster's eyes with the stun gun, no matter how much it struggled or punched. She kept shocking it until it was weaker and weaker, until it could no longer move or react, until its head turned into a puddle of black liquid, and until the two stun guns were no longer charged. Only then did Xu Anran let go and slump to the ground.

Sister Liu sat at the dining table, drinking water and watching the two fight. Looking at Xu Anran lying on the ground, Sister Liu smiled and praised, "You're really something, young lady. So, what do you want to ask?" Xu Anran didn't waste any words: "Who are the people in this neighborhood? Where did you come from? Why did you want to kill me?"

Sister Liu was quite straightforward: "The whole neighborhood is full of our people. We're here to monitor you and kill you. We come from a planet called Atam. Atam was destroyed by a meteorite impact, and we are the survivors. We wandered to this planet and wanted to take over. Everything went smoothly; we've already replaced many humans. Our plan was to kill you all before humans discovered us. But two days ago, the Atam people who replaced your uncle lost contact, which aroused suspicion in the person in charge of this city. They suspected that someone had discovered our existence, so they sent our team to investigate. After killing your cousin, we quickly found information about us on his phone, and your uncle's last phone call was to you. Your aunt and cousin are all dead, and you are the most suspicious. Then, through our people at the police station, we found your current address and put you under surveillance. Then I'll test you to see if you're still human or if you've already become one of us."

"So, the needle on the plate this morning was your test? Don't you have any other way of knowing whether I'm one of your comrades?"

Sister Liu smiled. "Once you're dressed in human skin, we won't be able to tell the difference. Is there anything else you want to ask?" Sister Liu walked over, making a move to help Xu Anran up, but Xu Anran pushed her hand away and swayed as she stood up. "Actually, I've always thought we don't need to be enemies. You have such a large population; you're not so easy to kill. We can coexist peacefully and survive together in this world. There are always two ideas among the Atam: one is to kill all humanity, and the other is to live in peace. I belong to the second, so don't be afraid; I can help you." Sister Liu followed Xu Anran to the sofa. Seeing that Xu Anran didn't resist, she held up a spatial ring and tentatively asked, "After you killed the Atam person disguised as your uncle, did you find this?" Xu Anran stared blankly at the ring and shook her head. "I didn't notice. What is this? Is it important?" Sister Liu didn't say anything, but instead reached out to grab Xu Anran's neck. With a soft thud, the black knife from her spatial storage was plunged into Sister Liu's throat.