"No problem, then thank you Brother Jiao." Geng Tongtong knew that there were hundreds of tons of grain in Jiao Bai's personal space, and he didn't care about this thing, so he didn't be polite to Jiao Bai.

The journey after that went was much smoother, and I didn't encounter any high-level creatures, even if there were occasional mutant beasts blocking the way, they were all first-level and second-level goods, and they were easily solved by the Thunderbirds. Bypassing the mountain beam, I finally saw the entrance to the bomb shelter.

A four-meter-high and three-meter-wide cave opens into a steep cliff face. The entrance of the cave is carved with six traditional Chinese characters of "4092 Project", and the font is swaying and elegant, which is very charming. The words were originally painted with red paint, but no one took care of them for decades, and the color had fallen off and was almost invisible.

Jiao Bai pointed to the handwriting on the cliff wall, and asked with some curiosity: "What does this four zero ninety-two mean?" ”

Revisiting the old place, Geng Tongtong's interest was very high, and he patiently explained to Jiao Bai, "I know this, Songjiang Electronics Research Institute used to be a military unit, and the code name was 4092. Later, the military streamlined its organization, and the institute was assigned to the jurisdiction of Songjiang Prefecture, which gave rise to the name of Songjiang Electronics Research Institute. In addition, this air-raid shelter was also built on September 2, 1940, in order to commemorate this day, these four words were engraved on it. It is said that these four words were written by Yan Heng, the original imperial military god, which is very commemorative. ”

In order to prevent rainwater from backing up, the air-raid shelter is higher than the surrounding ground, and the bottom of the hole is about half a meter higher than the road where Jiao Bai is located, and there is a cement slope in the middle for vehicles to enter and exit. Along the slope to the front of the air-raid shelter, the height of the cave is only two and a half meters, and the Thunderbird can not be used at all, and is simply left at the entrance of the cave by Jiaobai.

The wild boar opened the way in front, and Jiao Bai, Geng Tongtong, and Wang Zhengyuan and other zombies followed behind the iron-haired wild boar and entered the cave.

As the air-raid shelter went deeper, the light became darker and darker, Jiao Bai took out a few headlamps from the carry-on space and distributed them to everyone. The left side of the cave wall is smooth, and there are some traces left by the erosion of long-term flowing water, which should be the wall of the natural cave that originally existed, and the right half of the cave wall is uneven, and it is full of traces left by chisel and iron chisel. In the forties of the last century, Dayin was still in an agricultural society, and the industrial base was very weak, and the digging of this air-raid shelter mainly relied on manpower. Jiao Bai is a modern person, and it is difficult to imagine how people at that time could complete such a huge project with only their hands.

"Is there only one entrance to this bomb shelter?"

"I don't know, it's too big, I was young when I last visited, and I was tired after only visiting a few major tunnels, so I didn't go to see other places. But I remember that there was a plan of the layout of the bomb shelter at the fork in front, and I think all the exits were marked on it. ”

While speaking, everyone had reached the fork in the road that Geng Tongtong said, where the tunnel was divided into three and led to different places. The iron-haired boar didn't know which way to go, so he stopped here, waiting for Jiao Bai's next order.

Jiao Bai swept it with his headlamp, and sure enough, he saw the layout plan on the right side of the cave wall. This picture is painted with waterproof paint, after hundreds of years, the color is a little dull, but it has not fallen off, and the composition and handwriting on it can still be clearly distinguished.

According to the layout map, the entire air-raid shelter is divided into several major areas, namely the storage area, the living area, the scientific research area, the factory area, the area is amazing, it is not an exaggeration to say that it is a fully functional city in the cave. There are two exits, one is the one that Jiao Bai just came into, and the other exit is at the foot of the mountain on the south side of Sheshan, and the entire air-raid shelter pierces Sheshan. According to the scale marked on the layout plan, the total length of the entire air-raid shelter is more than 10 kilometers, and the total area of the caves excavated in it is more than 500,000 square meters.

In order not to get lost, Jiao Bai took out his mobile phone, took a picture of the layout on the cave wall, and then chose the cave on the right side and walked down.

Seeing that Jiao Bai had chosen the route, Geng Tongtong hurriedly followed, "Brother Jiao, the cave on the right leads to the depths of the mountain, what are you doing there?" ”

"I look at the annotation on the structural drawing, there is an underground river at the bottom of the mountain, is it true?"

Jiao Bai did not answer Geng Tongtong's question directly, but inquired about the situation in the belly of the mountain.

"Yes, and it's an underground river with a very large flow, and you can hear the roar from afar."

Hearing this, Jiao Bai became happy, this was the answer he wanted to hear the most. Jiao Bai wants to build a factory here to produce something that cannot be produced on the earth, or is not suitable for production. To build a factory, electricity is inseparable, and the original power plants in the last days are more advanced in technology, all of which are nuclear fusion generator sets. But the pit is that it uses the fusion reaction of helium-3 and deuterium, which can only be mined on the moon and is almost non-existent on Earth. Of course, Jiao Bai can't get helium-3, let alone helium-3, he can't even get deuterium, which is relatively easy to make, and there is no way to talk about resuming power generation in power plants.

But the existence of the underground river made Jiao Bai think of hydropower generation, as long as the flow of the river is high enough and the drop is large enough, it will continuously provide electricity to meet the needs of the factory.

The next road was not as smooth as before, and from time to time, a few mutant rats would jump out and attack Jiao Bai and his party. Most of these rats are first-class mutant beasts, the size of a puppy, with two unusually developed front teeth that protrude out of their lips, and their appearance is very ugly. Occasionally, a pig-sized one pops up.,It's a second-level rat king.,Will have some earth-based skills.,The attack is not high.,But it's extremely annoying.,Often make people disgraced.。 Fortunately, there are wild boars to open the way, and Jiao Bai and the city guard zombies are also very good in marksmanship, as long as they see the rat king coming up, they will be killed as soon as possible.

After walking for more than half an hour, some distance from the bottom of the mountain, you can already hear the roar of the water rushing down from a high place and smashing against the stones and water. Following the sound, I turned two more intersections, and finally saw the underground river marked on the structural drawing. The river is more than ten meters wide, the water is very fast, the flow direction is from west to east, and the source comes from a cave in the west. I shone it into the cave with my headlamp, and found that the cave was relatively narrow, and if I wanted to explore it, I could only take a boat upstream, and Jiao Bai was not here to explore, so he naturally would not explore the cave.

Walking downstream along the river, the cave is getting wider and wider, looking at the traces on both sides, the whole cave is formed by the erosion of the underground river, but now the flow of the river is not as much as it used to be, which leaves the open space on both sides.