Professor Yang Shimo explained the fractal theory to Hu Kehao and Uncle Liu, and they felt confused and completely incomprehensible. Hu Kehao asked with a puzzled expression, "Professor Yang, what are you weaving these fractal objects for in the laboratory?" ”

Professor Yang picked up a woven Sherpinsky carpet from the ground, draped it over Hu Kehao, and said: "Theoretically, the area of the Sherpinsky carpet is zero, and the length is infinity. Of course, we can't do this carpet indefinitely, and we can't achieve such a high level of precision. What happens if something has zero area? Professor Yang asked.

"The area is gone, so I shouldn't be able to see it, right?" Hu Kehao said as he draped the battered Cherpinsky carpet.

"A carpet without area is certainly invisible." Professor Yang said.

"Can I see him draped in a carpet? Could it be that he was wearing the emperor's new clothes, and only the wise and competent could see him? Fourth Uncle Liu said suspiciously.

"Because of the limitations of the process, it is impossible for the Scherpinsky carpet we make to be truly 0 in area, but it is enough to play an invisible role at present." Professor Yang wiped something on Uncle Liu's eyes, and Uncle Liu really couldn't see Hu Kehao.

It turned out that the Sherpinsky carpet made by Professor Yang was spelled by Master Hongdao, and it had an invisible effect on the fourth dimensional supernatural space. Those ghosts and evil spirits can only see things in integer dimensions, such as one-dimensional lines, two-dimensional faces, and three-dimensional three-dimensionals, and cannot see non-integer fractal objects such as the Scherpinsky carpet and the Cork curve.

In this way, people in the three-dimensional space cannot see the ghosts and evil in the four-dimensional space, but the ghosts and evil in the four-dimensional space cannot see the fractal objects in the real space, and they have invisible things for each other, which is considered to be even. Professor Yang smeared a potion on Uncle Liu's eyes to simulate the visual effect of ghosts and evil in the four-dimensional space, and he really couldn't see Hu Kehao in the three-dimensional space draped in the Scherpinsky carpet.

"Since this Shcherpinsky carpet has an invisible effect, can we wear it and go to the bank to get money?" Fourth Uncle Liu asked.

"You go and try it and see if the police will arrest you? This carpet will only make it invisible to the ghosts and evil spirits in the four-dimensional space, and visible to the people in the three-dimensional space. Professor Yang wiped the potion off Uncle Liu's eyes, and he could see Hu Kehao wearing a Scherpinsky carpet again.

Hu Kehao was amazed by Professor Yang's Scherpinsky carpet. After visiting the laboratory, Hu Kehao was about to go out with Uncle Liu to look for fire spirit grass, and Professor Yang presented a carpet to Hu Kehao, saying that if you encounter ghosts and evil things on the road, you can put the carpet on your body, and the ghosts and evil spirits will not be able to see him.

After walking more than ten kilometers to the northwest, Uncle Liu took Hu Kehao to the edge of a mountain cliff, which was more than ten meters high and very dangerous. Looking up, there were only scattered grass and trees on the cliff, and there was a fiery red mass halfway up the mountain. Fourth Uncle Liu said: "That's the Fire Spirit Grass." ”

Hu Kehao looked at the terrain and couldn't climb up from the bottom of the cliff, so he could only find a tree on the top of the cliff and go down the rope. There are many trees on the cliffs, and they grow very strongly. They found a tree, Hu Keha tied a rope to it, tied a dead knot, and then grabbed the rope and slowly approached the fire spirit grass, where Uncle Liu was on the top of the mountain to take care of. Hu Kehao descended halfway up the mountain, and saw the appearance of this fire spirit grass clearly, the size of Artemisia annua, the whole body was red, and there were eight branches on the main stem, and each branch had nine leaves, exactly the same as the picture drawn by Master Hongdao.

There was a crooked-necked tree next to the Fire Spirit Grass, and there was a clump of grass under the tree. Hu Kehao was afraid that the fire spirit grass would run away, so he prayed to it sincerely, then took out a small shovel, gently dug up the soil around the fire spirit grass, and pulled out the fire spirit grass with bright red roots and hid it in his arms. At this moment, a crow flew over from the air, holding a piece of meat in its mouth, directly ignoring Hu Kehao, and fluttered into the grass next to it.

Hu Kehao climbed the rope, came to the grass, cut through the grass with a shovel, and saw a cave, half a man high. Intrigued, he untied the rope from his body and climbed into the cave. The cave was cold, very dry, and the further you climbed in, the darker it became. After crawling for about six or seven meters, Hu Kehao turned on the flashlight and saw the big crow just now, standing next to a pile of white bones, and the meat in its mouth fell to the ground. The crow saw someone crawling in and let out a few strange screams, and Hu Kehao hurriedly turned off the flashlight.

With the faint light coming in from outside, Hu Kehao judged that what he saw just now was the bones of a dead man, the body had all decayed, but the skeleton was intact. The crow took three branches and stuck them in a small hole in the ground, and kept nodding in front of the bones, as if pecking, it turned out that the crow was sacrificing in its own unique way.

The white bone seemed to be sensed, and its body slowly stood up from the ground. The skull spun around, and those empty eyes seemed to see Hu Kehao, staring at him all the time. Hu Kehao was so frightened that he didn't dare to move, for fear that this white bone would rise up and harm him. This skull may have not seen a person for a long time, and has forgotten what a "person" is, thinking that he is a stone. After a long time, the skull turned and looked at the crow, as if thanking it for finding food for itself. The skeleton's mouth opened slightly, and the fresh meat on the ground slowly changed color, becoming a piece of rotten flesh, emitting a foul stench. It is the crow's nature to eat carrion, and the crow takes aside the carrion that has been sucked away from the bones, and pecks at it in a few bites.

Hu Kehao remembered the Scherpinsky carpet that Professor Yang gave him, and gently draped it over his body to prevent the demons from seeing him. After the skull had finished enjoying the sacrifice, it turned its head to look at Hu Kehao, and when he saw that there was no one here, he turned around again. Its legs are crossed on the ground, resting its head against the stone wall. After eating the carrion, the crow circled twice in the hole and flew out.

Soon, a white light shot into the cave, landed in front of the skull, and turned into a white-bearded old man, with long hair tied and dressed in white, with an extraordinary appearance, and said to the skull: "General, what are you thinking about now?" The King of the Shadow Eater thinks so highly of you, and if you submit to him, he will surely regenerate you, and make you have a good skin, like a white bone in this cave! ”

"Needless to say, I'm at odds with that Yin Devouring King!" The skeleton's throat made a strange sound.

"After hundreds of years, the hatred between you should have been resolved a long time ago! In my opinion, you might as well join forces to create the glory of the past! The white-bearded old man said.

The skeleton laughed: "As the mountain god here, you enjoy the incense of the people, you should be the representative of justice, but I didn't expect you to take refuge in the Yin Devouring King, endanger the people, and make such contemptuous remarks!" I see that you are sinful and heaven and earth do not tolerate it! The people in the vicinity are willing to eat your meat! Fortunately, justice in the world is still there, and the Yin Devouring King will not last long. Now that you have surrendered and betrayed, you can only hide and shrink your head, and beg for food and clothing; How dare you speak in front of this seat! Hao Shou Pifu! Bearded old thief! Thou shalt return to the Nine Springs on the same day, and what face will you see the Jade Emperor of the Heavens! The old thief retreats quickly! The Teachable Yin Devourer King will fight with me! ”

When the mountain god heard this, his chest filled with anger, he screamed, and fled out of the cave in embarrassment.