It stood at the door for a long time, then fell into extreme pain, constantly shaking its head. After about ten minutes, its expression returned to its original emotionless state.

It slowly moved away from the dilapidated residential building filled with memories of its human days, aimlessly wandering the streets, no longer following the drone to the garbage dump. Even when the drone circled around its head for a long time, it remained indifferent.

"It... became like this because of that agreement, right?" Jiayang looked at it in the footage, his tone seeming somewhat reluctant.

I remained silent. Linyan had never mentioned anything about human experiments in the research institute to me. I guessed he probably didn't know either, otherwise, he wouldn't have failed to recognize this three-time mutated monster zombie the first time he saw it, nor would he have kept it from us. The only explanation is that this is also a confidential experiment of the upper levels of the institute.

I sighed as I looked at it, then initiated the drone's return.

We thought it would probably be fine the next day, back to its usual self, begging for food on our terrace. But for several days in a row, we didn't see it again. The zombie bodies downstairs remained piled up, and even sending the drone out to search for it yielded no results.

Aside from the increasingly strong stench, our days returned to calm.

This continued until the 106th day of the zombie outbreak, and it had been over half a month since Linyan and Xinyan were rescued.

The military helicopters finally arrived again, this time several in succession. Jiayang and I exchanged a glance, seeing understanding and joy in each other's eyes. This time, they were probably really going to carry out a major extermination operation, the research must have been successful.

After about ten minutes, I heard the sound of keys turning in the lock outside the door, followed by the final sound of a fingerprint being scanned to open the door.

With a "fingerprint correct, door unlocked," Linyan, dressed in a white coat, appeared in the entrance.

At that moment, I felt a bit dazed, as if he had just left home as usual to work at the institute, then returned home after finishing a new research project in his work clothes, standing in the entrance, taking off his work clothes while watching me run towards him with a smile.

"Xiaozi."

His familiar call brought me back from my thoughts, tears uncontrollably streaming down, reminiscent of many times before yet somehow different.

I threw myself into his arms.

He patted my head, smiling softly, "We can soon return to normal life, the research was successful."

I hugged him, burying my head in his chest, the scent of disinfectant still there, unpleasant yet comforting.

"This time, they've come for the extermination, right?" I heard Jiayang say.

"Yes. They're also using City A for a large-scale experiment. The infrasound waves can indeed have a very intense effect on zombies, even without using military ammunition, without damaging any city structures, it's the best way to eliminate zombies."

"Then why did you come back too?" I asked, looking up.

"I'm one of the main developers, so I came to assist with the equipment's use. Also... to bring you all to the safe zone. After all, infrasound waves can also have serious effects on the human body, so you can't stay here anymore. The military has also sent out more rescue teams to save the survivors who haven't been rescued from the city yet."

As we packed our things, I suddenly remembered the mutated zombie that had disappeared without a trace.

"Do you know... what kind of human experiments your institute has conducted?" I asked Linyan, who was helping me pack.

He looked at me puzzled, genuinely unaware, "Human experiments? The institute has never publicly admitted to conducting human experiments, it's not allowed... only drug experiments are permitted, like the side effect tests conducted before each drug is released. But those are usually publicly disclosed. Why do you ask?"

I recounted in detail what I had seen that day to Linyan, leaving him shocked.

"So you suspect that this zombie virus outbreak might be caused by human experiments in our institute?"

I nodded, then shook my head, "I initially thought so, but then I remembered, the initial discovery of the zombie virus didn't start with animals, right? Or was it the water source. I just feel... there must be some connection. But I can't figure out what it is."

The helicopter outside sounded its horn, seemingly urging us.

"Let's go to the safe zone first, we can't figure anything out right now," Jiayang said, shouldering the packed bag, holding Little Gu in his arms, standing at the door.

Linyan and I stopped our conversation, hastening our movements.

As we safely ascended from the top floor to the rescue helicopter, the sky was already dark. I gazed at City A under the setting sun, my thoughts still tangled. If this virus was man-made, even if the city restored order, what would happen in the future? Will peace truly endure?