According to the address provided by Mrs. Han, Lin Feng and Han Xi came to the family building of China Construction Fifth Bureau.

"Building 2, Unit 3......" Han Xi looked around, pointed to a small red brick building not far away, and said, "That's it!" ”

"Let's go!" Lin Feng took the lead.

The two quickly entered the small building and knocked on the door of Niu Jianguo's house.

Knock knock!

However, no one responded.

Knock knock!

Knock again, but there is still no movement.

Lin Feng wondered in his heart, is there no one at home?

Bang bang bang!

Han Xi slammed the door hard and shouted inside, "Is there anyone, is there anyone!" ”

"Ahem, cough, cough......" At this time, a cough came from behind the door, and the voice sounded, "Come on, don't knock." ”

The iron door opened with a "squeak", and an old man with a bald shaving appeared in front of him, looked at the two people outside the door vigilantly, and said in a deep voice: "I don't buy health products, don't come back in the future, day by day!" ”

After that, the door is closed.

"Don't, don't!" Han Xi hurriedly propped his hands on the door and explained, "We don't sell health products!" ”

The old man was stunned: "Don't sell health care products?" So what do you want to do? ”

Han Xi said: "Let me confirm first, you are Niu Jianguo of China Construction Fifth Bureau, and your father is the famous chief engineer Niu Aihua, right?" ”

Seeing this girl tell her family history, the old man wondered even more: "How do you know, who are you?" ”

Han Xi took out the letter of introduction and handed it over: "You'll know after reading it." ”

Niu Jianguo put on reading glasses hanging on his chest, squinted at them, his brows gradually wrinkled, and when he looked at Han Xi again, his eyes were full of surprise: "You are the granddaughter of Old Madam Han?" ”

Han Xi smiled and nodded: "That's right, this time it was grandma who asked us to visit you." ”

Niu Jianguo returned the letter of introduction to her and asked, "What are you looking for me to be a retired bad old man?" ”

"That's right." Lin Feng took over the conversation, "We are students of Jinghua University, and we want to learn about the construction process of the library from you. ”

Hearing this, Niu Jianguo asked: "Hey, the library was built thirty years ago, what are you doing with these old sesame rotten grains?" ”

Lin Feng secretly thought.

Do?

Of course, it's to find out what the source of the underground aura is, otherwise why spend half a day looking for you?

"If nothing else, we just want to know more about the history of the school's construction, so we chose the library as the research object." Lin Feng said with a smile.

Niu Jianguo sighed: "It's not the Taihe Hall of the Forbidden City, what is there to study in a broken library?" ”

"Well, since you have to know, then I'll talk to you and come in."

Niu Jianguo had better be quiet and didn't like outsiders to disturb him, but these two young people were introduced by Mrs. Han, so this face has to be given no matter what.

After all, when his father was criticized as a reactionary authority, Mrs. Han fought hard and helped him avoid a disaster.

"You're the only one at home?" Han Xi looked at the empty room and asked.

Niu Jianguo said while pouring water: "My wife died early, and my children are all working in other places, and I can't come back a few times a year." ”

"Alas, it's good to live alone, clean, and don't make a fuss."

Although he said so, there was a deep sense of loss in his tone.

When people reach old age, who doesn't want their children and grandchildren to be around their knees, and who doesn't want to enjoy the joy of family?

To be pure means to be lonely, and not to make a fuss means to be lifeless.

After living in this environment for a long time, the whole person will become depressed and depressed.

"I don't have tea at home, so let's drink some hot water." Niu Jianguo served two cups of boiled water.

Lin Feng smiled and said, "You don't have to be polite, let's just ask a few words, and leave after asking." ”

Niu Jianguo twisted a piece of cigarette paper, poured some tobacco leaves, and said while rolling a cigarette: "If you have anything to say, just ask, I will tell you everything I know." ”

Lin Feng went straight to the point: "I heard that the library was originally designed with three underground floors, why is there only two floors now?" ”

Niu Jianguo lit a cigarette and took two puffs: "Three layers were designed at the earliest, and then it was changed to two layers. ”

Lin Feng was stunned, isn't this the same as not saying anything?

"There's got to be a reason, right?" Han Xi asked.

"Shhh Niu Jianguo exhaled a puff of smoke and said, "The biggest reason is that a continuous giant karst cave was found underground, and if it was forcibly built, the amount of work would be too large, so my father later changed the plan and reduced the three floors to two, so that the library could be completed before the school anniversary." ”

Hearing this, Lin Feng and Han Xi glanced at each other, and said in unison: "Cave? ”

Niu Jianguo nodded: "The entire Jinghua University is built on a large karst cave, criss-crossing and rugged below. ”

Lin Feng asked, "When the school was built before, didn't you find that there was a karst cave underneath?" ”

Niu Jianguo said: "The cave is more than 50 meters deep, and ordinary buildings can't be involved in such a deep depth, so no one has been deeply explored. ”

"If it weren't for the construction of the library thirty years ago, I'm afraid no one would know this secret by now."

Han Xi was uneasy: "Oh my God, the whole school is located on top of the cave, what if it collapses?" ”

Niu Jianguo waved his hand: "No, the thickness of fifty meters is enough to support a skyscraper hundreds of meters high, let alone a school." ”

"After the discovery of the underground cave, my father took dozens of engineers to do a comprehensive physical examination of Jinghua University from the inside out, believing that the strength of the earth's crust is enough to support the school building, and there is no problem of collapse."

Han Xi patted his chest: "Good guy, I'm scared to death, it's okay, it's okay!" ”

Lin Feng then asked, "What's in the underground cave?" ”

Niu Jianguo extinguished the cigarette butt and tried to recall the original scene: "There is a dark river and some unformed crystals, and the others are nothing." ”

Lin Feng frowned secretly.

Naturally, the dark river can't emit aura, and thinking about it, those majestic aura are probably related to the crystals in the cave.

But the crystal is just quartzite, to put it bluntly, it is a stone, how can it contain aura?

It seems that if you want to find out, you can only go to the underground cave yourself.

"Just now you said that Chief Engineer Niu has led people to explore underground karst caves, so there should be a passage in and out, right?" Lin Feng asked.

Niu Jianguo nodded: "Of course, doesn't the school have an artificial lake, there is a small white house in the northwest corner, and from there it can be connected to the underground." ”

Lin Feng said: "Isn't that for overhauling pipelines?" ”

Niu Jianguo smiled: "It's just to hide people's eyes, you can't tell everyone that there is an underground cave here, right?" The students are so curious, they must all want to go down and see the excitement, so it's not messy? ”

"Huh?"

Niu Jianguo seemed to notice something, and his face turned cold, "Why are you asking this?" I warn you, don't make a bad idea, the underground cave is very dangerous, once you get in, don't think about it again! ”