The thing is actually very simple, this so-called underground passage is actually built around a tower-shaped building. The entire tower building has a total of 18 floors, which is about 50 to 60 meters underground according to the calculation of three meters per floor.

Strangely, though, although the tower is a monolithic building, for some unknown reason, the builders built separate doors for each floor. Just like the room that Wu Yu entered last night, it was actually the third floor of the underground tower, and the entrance was connected to the athletes' passage in the gymnasium.

It took Yu Chen about half an hour to tell Wu Yu the basic structure of the entire underground tower, and it was not until he said the details of each floor of the tower that Wu Yu could understand.

However, as for what this underground tower was for, in fact, Yu Chen and Lin Feng were not very clear, just said that their memories were connected together, and they discovered this place. That is, they had been here before they lost their memories.

Wu Yu looked at the surrounding walls, and felt that Yu Chen's words were a bit suspicious of nonsense, after all, it was not realistic to dig out more than fifty meters underground. It's very close to the Hunhe River, and if you dig to that depth, you'll inevitably touch the groundwater, and before you can finish it, you'll have to be flooded.

But without waiting for Wu Yu to ask, Lin Feng brought a drawing, although Wu Yu had never learned how to read architectural drawings, but Wu Yu's ability to read drawings was very good, Lin Feng simply said what some lines represented, and Wu Yu could almost understand it.

This drawing is a very traditional kind of paper product, but judging from the waterproof membrane on it, it is obvious that someone got it later, and it will not be too long.

After reading the drawings, Wu Yu secretly admired the designer's brain, the entire underground tower was actually built with steel structures on the ground, and then hollowed out layer by layer underground, so that the entire tower body sank into the ground little by little. This process alone may not be completed in a few years.

Of course, the premise is that the construction time is not too long, if it was built by the ancients, then Wu Yu will admire it more.

The passages on each floor were dug in advance, and after the tower sank to the designated position, the architects connected the passages to the doors of the tower layer by layer. As for the possible groundwater that Wu Yu had thought about before, the architects used the simplest method.

Now that I think about it, there must be a lot of dicks among these architects, otherwise they wouldn't have used such a strenuous method.

In fact, it is not as difficult as it seems, the passages connecting the tower are closed, after the tower reaches the designated position, the repaired pipe is connected with the tower by manpower, and then the channel is opened to drain the water that seeps in. Since there is only one section of the pipe, there will not be much water, and it is much easier to build a channel inside the pipe.

This drawing is only a general description of the underground building, and does not have any layout of the interior of the tower, in which the tower is just a symbol.

After reading the drawings, Wu Yu immediately had a question in his mind, and hurriedly asked: "Since you don't know what this thing is for, what did you find in it when you explored other areas before?" Is it possible that these things prove the role of the tower itself? ”

Yu Chen sighed: "The first nine cities are basically experimental places for all kinds of secret techniques, there is a layer of professional ghost faces, and there are some secret techniques that we have never heard of. The bottom all the way up to the sixteenth floor was empty, and we checked it many times to make sure there was nothing. ”

Wu Yu nodded, but when he thought that he went to the third floor last night, he asked, "The third floor I went to last night, why is it empty?" ”

Lin Feng suddenly interjected: "What was transported away by Xiao Jie and them was originally a part of the orthodox Dao art laboratory, and then Xiao Jie and they wanted to learn, so Yu Chen let them transport the things away." ”

It seems that this should be irrelevant, otherwise Yu Chen would not have let Xiao Jie move away so easily, after thinking about it, Wu Yu asked, "Then you found out that the resentful soul is on this layer?" ”

Yu Chen nodded: "That's it, we only found out after we came in, there are tens of thousands of resentful spirits wandering around the entire room, and the walls of the house are carved with a certain spell that binds them. Fortunately, I reacted quickly at the time and locked them all in time with the Soul Lock, otherwise we would have died on the spot. ”

Wu Yu looked around, because there was light bulb lighting, he could vaguely see that there were indeed some strange patterns painted on the wall. However, Wu Yu couldn't understand any of them, although he studied the part about the talisman in Taichen's notebook, it seemed that the pattern here had nothing to do with the talisman.

After thinking about it, Wu Yu asked again: "Is there nothing else here except for resentful spirits?" ”

Yu Chen nodded: "Nothing, but we later found the passage down, which is the only passage to enter the eighteenth floor." ”

Wu Yu was stunned, the previous seventeen floors were all separate passage entrances set up on the outside, why did they suddenly change when they reached the eighteenth floor? If it's because you want to confuse intruders, then those who can pass through every other floor in front of you will definitely find the entrance here.

If it is said that there is groundwater underneath and there is no way to build an external channel, this is obviously not reliable. The construction method has been seen on the drawings before, and it is clear that the groundwater is not a technical problem for the people who built it.

After being silent for a long time, Wu Yu said, "Then have you speculated about what will be down there, or how big the area will be below." ”

Lin Feng nodded: "I guessed, because the door here was discovered after our memories were spliced, which means that the three of us finally went down inside, and the loss of memories started there." So we guess that it should be a more important experimental place inside, and from the current analysis, it may be related to the soul stack. ”

When it came to the Soul Stack, Wu Yu immediately thought of the Fox Immortal Hall in his mind, and vaguely remembered the statement about the Soul Stack on the wall of the Fox Immortal Hall. The kind of fusion of souls in order to achieve the effect of immortality seems very unreliable.

However, when it came to the soul stack, it also suddenly made Wu Yu think of the changes in Yu Chen's body, this kid has two souls in his body, which is impossible in ordinary people.

Two souls in one body, in ancient times called the ghost upper body, whether the upper body is a resentful soul or the soul of an immortal beast, or another person's wandering soul, it will make people's bodies produce a similar phenomenon of rejection.

If the soul of the latecomer is weaker, it will not be long before it will be expelled from the body by the soul of the main body. If the soul of the latecomer is stronger, or with resentment, then there will be a phenomenon of ghosts on the body. For example, talking gibberish, or doing things that ordinary people can't.

Whether it is the former or the latter, the upper body of the soul will cause some damage to the body, and after a long time, the body can not withstand such a great pressure, which will make people become skinny and slowly move towards death.

However, at present, it seems that the soul in Yu Chen's body does not seem to have brought him much harm, which means that according to the theory of the soul stack, he should be a successful soul stack.

Thinking of this, Wu Yu's mind couldn't help but be shocked, and he immediately concentrated and opened his eyes. This kind of thought is a bit terrifying after all, so Wu Yu didn't tell Yu Chen what he thought, but instead opened the Heavenly Eye and looked at Lin Feng and Xue Hao beside him, and by the way, he also glanced at the hidden person in the corner.

Xue Hao's soul was a little abnormal, but it was not Yu Chen's two souls in his body, but around Xue Hao's body. In terms of color, the mass of souls was a dark blue, and it seemed to be denser than human souls.

Wu Yu knew what it was, and there was a special note in Yu Chen's notes about the Xue family's Baojia Immortal, and Buddhism called such a soul an obsession soul, a kind of soul that still has an obsession in his heart after death. Generally, they will leave only when they fulfill their wishes, and the immortals who want to come to the Xue family should be some souls who are obsessed with protecting the Xue family.

When he turned to Lin Feng, Wu Yu couldn't help but gasp, two souls also appeared on Lin Feng's body, and they were extremely similar to Yu Chen, one was concentrated near the heart, and the other was gathered on the top of his head. This is completely different from the normal distribution of souls in the human body.

The soul of a normal person is mainly based on a human head, and then distributed in various parts of the body, but Lin Feng and Yu Chen don't seem to have the meaning of distribution at all. It was as if there was no soul distribution in their limbs, and only the head and heart had souls in their whole body.

Wu Yu didn't dare to make a conclusion, and quickly turned his gaze to the person in the corner, the strange thing was that the person seemed to exist in the way that Yu Chen often used, that is, the yang energy was mobilized to the surface of the body, so that he was in a state of disappearing.

In this case, Wu Yu's Heavenly Eye couldn't tell how many souls the other party had, and the last time Yu Chen disappeared, Wu Yu used the Heavenly Eye to see, and he only saw the phenomenon of Yang Qi mobilization, but he couldn't see Yu Chen's soul at all.

After thinking about it, Wu Yu said to Yu Chen: "Brother, you let that buddy in the corner come out for a while, I always feel that I don't have a score in my heart when he hides it like this." ”

Yu Chen frowned and glanced at Wu Yu, obviously a little strange. But he didn't pay much attention to it, but said to the corner, "Come out!" ”

There was a 'um' response from the corner, and then a figure walked out of the corner, Wu Yu slowed down and couldn't help but be surprised. Unexpectedly, that person turned out to be Xiao Song, the neighbor of the shroud shop, and he was there when we went to the Fox Fairy Hall last time.

Wu Yu remembered that Xiao Song didn't understand anything last time, but this time he saw that he had actually learned the method of Yu Chen's disappearance, so he couldn't help but look at Xiao Song again.

This is not the time to study Xiao Song, Wu Yu hurriedly opened his eyes to look at Xiao Song again, this time Wu Yu saw clearly, Xiao Song's body was the same as a normal person, there was only one soul.

Seeing this scene, Wu Yu was shocked, and a chill arose for no reason, could his conjecture be right?