After class, I carefully collected the red substance from the test tube into a small flask and secretly placed it in my backpack. After school in the afternoon, I went straight to Grandpa Li's house, wanting to ask if he knew what this substance was.

Grandpa Li took the small flask containing the red substance and examined it carefully before opening the lid and sniffing it. "Where did you get this from?" So, I recounted everything that happened in the lab to Grandpa Li. After listening, Grandpa Li smiled and said, "It seems like there's definitely a problem in the laboratory."

"Oh? A problem? Do you know what this is then?" I became interested in the flask.

"Hehe, the red substance in here is called Ming Blood. It looks and smells like blood, but its essence is still the substance you obtained from the experiment. It's just that through certain means, people are made to feel like it's blood."

"Ah? So, you're saying that the substance inside isn't actually red, but our perception is wrong?"

"Yes, you can understand it that way. In fact, everything we perceive in the outside world has a significant deviation from reality. Flowers are red, grass is green, these are all the information we perceive through our eyes, and our perceptual abilities are influenced by many factors in the space we live in. Everything around us is actually made up of five elements: metal, wood, water, fire, and earth, in different forms, formed through billions of years of change into the current environment. Our perception of everything around us is formed under this environment and aura. If we change the aura, what we see, hear, and feel may be completely different. Understand?"

"Not quite clear, you spoke too fast..." I scratched my head while looking at Grandpa Li.

"Let me put it this way." Grandpa Li thought for a moment. "Take the yellow paper your older brother usually uses to write charms, for example. You usually see it as yellow, but if you put it under blue light, what you see is black instead of yellow. Do you understand that?"

"I've seen that before, now I kind of understand. Something might look different in different environments, and our perception of everything around us is just a reflection of the current atmosphere on Earth. If we change the atmosphere and environment, then things might not look the same as they do now."

"Yes, that's the idea." Grandpa Li nodded with a smile, looking very pleased with me. "This kid really gets it."

"So, the substance in this flask is actually blue copper hydroxide (formed from copper sulfate and sodium hydroxide), but someone changed the atmosphere inside to make us have the illusion that it's something else."

"Yes, but it's not necessarily someone who changed the atmosphere inside. What you see here is called 'ghost covering eyes,' and most of the time, it's the work of spiritual beings that exist in another space." Grandpa Li looked mysterious.

"Ah? Ghost covering eyes? Are you saying there are spirits in the lab?" I was very surprised.

Seeing my expression, Grandpa Li smiled and said, "What's so strange about that? In fact, there are many souls around us, but they usually don't disturb people's lives. Since there are spirits disturbing you in the lab, there must be a reason for it. From what you just said, it seems that a spirit is only interested in a certain girl, indicating that there must be some kind of connection between them!"

"No way... Sun Li is just a high school student, could a spirit like her?"

"Come on, if it liked her, would it come to scare her every day? Usually, spirits have grudges against people. Young man, do you like her?"

"Don't talk nonsense." My face turned red. "So what should we do? Will the spirit harm our classmates?"

"Hehe, maybe. If there's deep enmity between them, it might not only harm her but also take her life." Grandpa Li continued with a mischievous smile, "You seem to care about her a lot, it seems like you're interested in her!"

"Don't talk about those useless things. I haven't even talked to her, but since I've encountered this, I should help."

"Oh? Young man, you really have a chivalrous heart. That's right, whenever we encounter such things, we must deal with them. Tomorrow, take a compass and go to the lab to measure and see if there's a problem with that wall."

"Okay." I felt like a warrior preparing for battle, full of determination.

The next day, I rushed to school early with the compass. The compass, actually a compass, is said to have been developed by Prime Minister Feng Hou during Emperor Huang Di's war against Chi You. Initially, it only indicated directions, but later, after Yang Junsong created the Tianpan and Laibuyi created the Renpan, it formed the most basic three layers of heaven, earth, and human in the compass. Then, various schools added corresponding things on it according to different purposes.

Unauthorized duplication: this tale has been taken without consent. Report sightings.

I used a four-layer compass, with a square base representing the earth, a circular middle representing heaven, known as the heaven round earth square. The place where the compass is placed is called the Tianchi, and one end of the compass is like a pair of small cattle horns, indicating the north, while the other end points south. The red part on the compass represents auspiciousness, and the black part represents danger.

The campus in the early morning was very quiet, with only a few boarders reciting words on the playground or under the big trees. I locked my bicycle and went straight to the laboratory behind the teaching building.

The laboratory was very deserted in front, with no one around. Although the weather in October was warm, I immediately felt a chill when I arrived here. The laboratory door was locked, so I looked inside through the window. It was very dim inside, and various experimental equipment lay quietly on the white experimental table. I took out the compass, laid it flat against my mouth, and measured from the outside, everything seemed normal. Then I walked to the entrance of the laboratory, looked at the direction of the door, and didn't see any problems. Since the door was locked and I couldn't get in, I had to wait until class to find an opportunity to measure inside. So I put away the compass and walked towards the teaching building.

Physics experimental class was in the afternoon and also held in that laboratory. Since there were many people in class, I never had the chance to use the compass to measure the room. When class was about to end, I quietly pulled the latch of a small window, preparing to come in after school to investigate the situation inside the room.

"Ring!" School was over, and I volunteered to help the teacher clean up the laboratory. Finally, I watched the teacher lock the door before feeling relieved. After school in the afternoon, I waited for a while, seeing that most of my classmates had gone home, and then I came to the laboratory and jumped in through the window.

Because the front was a tall teaching building, blocking the sunlight, the laboratory was always so dark. After I entered, I felt that the temperature inside was significantly lower than outside. So, I quickly took out the compass, laid it flat against my mouth, and walked slowly from the door into the room.

The layout of this laboratory was north-facing and south-facing, with the door in the middle and very tall, like a large warehouse. I walked slowly along the wall, and just as I was about to approach the north wall, the compass pointer suddenly pointed to the black area and began to shake. "Oh? Indeed, there's a problem with this wall." I thought to myself and continued to walk forward. When I reached the position where Sun Li usually sat during the experiment class, the compass pointer suddenly rotated a circle and shook violently. I carefully observed the snow-white wall next to the table. There was a concrete pillar here, so I picked up the compass and measured near the pillar. The pointer shook violently. "Hehe, it's here!"

When I got home at night, I told Grandpa Li everything that happened in the laboratory.

"It seems that there must be a secret hidden in that cement pillar." Grandpa Li put a filtered cigarette in his mouth, and I quickly lit it with a match. This was a cigarette case I bought for Grandpa Li, advising him not to smoke from a tobacco bag as it was bad for his health. Grandpa Li was very open-minded and easily accepted and liked this new product of the new era.

"Do you mean that there are some souls sealed inside the pillar? Should we unseal them and help them reincarnate?" I asked.

"You put it too simply. When was this house built?" Grandpa Li asked.

"I heard it was built at the beginning of the reform and opening up. It was originally intended to build a large ammunition depot, but as soon as this one was built, it started. After the reform and opening up, the current Foshan Middle School was built there. Due to the large and solid nature of this building, it was left behind." I heard all this from the class monitor Wang Jianchao. His family has always been near the school, so he is very clear about the situation there.

"Yes, you count it, this house was built for less than twenty years. At that time, who could seal a soul inside a pillar? I think it's not that the soul is sealed inside, but that it doesn't want to leave. From its attitude towards Sun Li, it seems to hate her very much." Grandpa Li explained his point of view.

"But Sun Li is only sixteen this year. When the house was built, she hadn't even been born yet. How could a soul know her?" I asked with some doubts.

"Yeah, so we must understand the relationship between them in order to come up with the best solution." Grandpa Li said, "By the way, how much do you know about Sun Li?"

"Her family is in the county town of Foshan. Her father passed away a few years ago due to illness, and her mother runs a small restaurant. She also has an older sister who is two years older than her."

"Oh, I see. It seems that we can't get any clues from her either." Grandpa Li thought for a moment, then suddenly smiled mysteriously and said, "Then why don't you become her son-in-law?"

"What are you talking about?" I was teased by Grandpa Li, feeling embarrassed. "So what should we do? Will the spirit harm people?"

"Well, it's very likely. It seems to be a vengeful spirit. This time it's just using a ghost covering eyes, but next time it might even cause a sulfuric acid explosion, which is not impossible." Grandpa Li continued with a serious tone, "Since you care about her so much, it seems like you have some interest in her!"

"Don't talk about that. I haven't even talked to her. But since I've encountered this, I should help."

"Oh? Young man, you really have a sense of justice. That's right, we must deal with such things whenever we encounter them. Let's make him speak out the reason for staying here by himself, and then find a way to resolve it."

"Let him speak out the reason by himself? Can you understand the language of ghosts?" I asked in confusion.

"Hehe, if I could understand the language of ghosts, I would be a ghost myself. But I can make ghosts speak human language, so we can understand." Grandpa Li said with a smile.

"Make ghosts speak human language? Could it be... Could it be that you let it possess someone else and talk to us?"