The Eye in the Lock

Cheng Li set down his toolbox, skillfully preparing to unlock and replace the lock. After all, A Qiu often lost both his main and spare keys.
But this time, before he could even take out his tools, A Qiu hastily reached out to stop him.
The young man looked distressed, his eyebrows drooping, and said, "No, Brother Cheng, I have my key today."
Cheng Li couldn't help but laugh, "Then why did you call me?"
A Qiu hesitated, glancing at Cheng Li, as if he had a thousand words to say but didn't know where to start.
This hesitant demeanor made Cheng Li a little suspicious. He looked at the young man for a moment, then seemed to realize something and blurted out, "Could it be… you like me? I'm a married man, you know."
A Qiu was speechless, "I know, the first time you came to unlock my door, I complimented your good looks, and you already told me you had a spouse."
"Brother Cheng, let's talk seriously. Do you believe there's something in this world that isn't human?" A Qiu lowered his voice, looking both panicked and mysterious, somewhat abnormal.
Cheng Li zipped up his toolbox, casually replying, "Of course. Cats, dogs, tigers, lions… none of them are human."
As he spoke, he prepared to leave. A Qiu seemed very eager to talk, and surely at length, but Cheng Li had no intention of staying to listen. Since there was no lock to open, he needed to go home early to cook dinner. His spouse had said this morning that he would get off work early to eat together.
But before he had taken a few steps, Cheng Li suddenly felt his leg being tightly hugged. He looked down and saw A Qiu's crumpled face, looking as if he was about to cry.
"Brother Cheng, please, I'm a migrant worker, I don't know anyone here, I don't know who to tell about this. Lately, I've always felt like someone is watching me in the house. Someone watches me when I eat, someone watches me when I shower. I've closed all the curtains, but I can still feel it clearly." At this point, A Qiu's voice choked up, "Today, when I opened the door, I suddenly felt something stuck in the lock, and I couldn't open it. Then, then guess what I saw!"
Cheng Li said indifferently, "Mm-hmm, I'm guessing you saw the lock."
A Qiu: "Brother Cheng!"
"It was an eye! A real eye! The whites, the pupils, all clearly visible, I really saw it!"
Cheng Li comforted him, "Perhaps you're just too stressed. The lock is so small, even with 20/20 vision, you wouldn't be able to see an eye inside."