Walking out of this seemingly ordinary but very extraordinary wild forest with Yudong, he didn't go far before a zigzag and winding water appeared in front of him.

This is the first time I have seen water since entering Lethe. I wonder if it could be the legendary Lethe River? Qin Zhen and Gu Jie hurriedly ran over, and when they got closer, they couldn't help but be surprised. This water is really flowing backwards from the bottom to the top!

"This—this is Lethe!" Qin was shocked. I thought to myself, what would it be like if Master Newton saw this picture? His law of gravitation is complete here!

Unexpectedly, they really saw the Lethe River flowing upwards with their own eyes.

The water here is clear, the stream is murmuring, and the water flow that seems to be infused with the spiritual energy of heaven and earth is rushing upwards in such a majestic manner. It's as if there's nothing out of the ordinary about it.

The sparkling water surface has an elegant pale green. Due to the different depths of the water, the slightly deeper areas will turn pale blue. The whole stream of water flows between blue and green, making people feel like a fantasy.

There are all kinds of strange peaks and strange rocks around, or like sheep's horns emerging from the water, or like humps blocking the stream, or like turnips planted upside down, the scene is myriad, each with its own beauty.

Looking up, the rushing waterway winds its way through the rocky crags into deep caves, and loops around the mountain through the slits of the rocks. It seems to be a three-dimensional Chinese landscape painting, and the depth of the painting is where the ultimate Nine Heavens --- Hundred Ghosts and Demon Lords are located.

I don't know why, Qin Zhen stood beside Lethe River like this, and his mood was difficult to calm down for a long time. Looking at Lao Gu on the side again, he actually sobbed with a handful of snot and tears!!

This surprised Qin Zhen! The heart said that this thing is being possessed by a ghost again?! When he was a child, he was beaten the most, and I never saw him cry like this! Except when Wang Bin died, how could he have cried like this?!

"This ...... Brother, whether you are a man or a woman, what sad things can you talk about...... Please don't toss my hapless brother, okay? Qin Zhen chattered to Lao Gu with a low posture and sincerity.

Lao Gu was stunned for a moment, then wiped his snot and scolded: "Qin Zhen, are you/your mother sick?" Also this brother? Where did you learn these words? What the hell are you doing?! ”

Qin Zhen is also a monk of the second zhang who is confused, listening to the meaning of this, this is Lao Gu! So he also scolded angrily: "Am I sick or are you sick?" You are so unjust watching the water flow here and crying?! ”

Unexpectedly, Lao Gu also scratched his head in confusion and said, "I don't know why...... I always feel very uncomfortable, especially uncomfortable! I remembered a lot of people and a lot of things......"

Hearing this, Qin Zhen didn't care about blaming Gu Jie. It's about starting to feel your heart. He was surprised to find that although he didn't cry bitterly, he was also very disappointed and uncomfortable.

Coupled with being reminded by Gu Jie just now, the faces that had saddened him in the past began to appear in his mind. For example, Wang Bin, Chen Feng, and Lao Shen......

Thinking about it, Qin Zhen didn't even realize that his eyes were red, and sadness came from it.

Suddenly, Qin Zhen felt that his collar was being pulled backwards with a strong force! It turned out that it was Yudong who pulled the two of them back from the edge of the stream!

It's not over when he dragged it back, and then Yudong slapped them one by one, slapping them in the face lightly and heavily! He also shouted loudly: "Wake up!!" ”

Qin Zhen felt that his melancholy and sentimental feelings were suddenly interrupted. He looked at Yudong a little confused, not knowing why he was doing this.

But Yudong didn't say a word, and pulled them away from the stream for some distance. After walking away for a while, Qin Zhen felt that his mood was a little more relaxed. But still with a deep sigh he said, "What's going on...... Why do I suddenly feel not in a good mood......"

Yu Dong saw that Qin Zhen and Gu Jie had become a little more normal, so he let go of them, looked at the water in the distance and said softly: "It turns out that this is the true meaning of Lethe River......

"Huh? What's the point? What the hell is going on? Qin Zhen wiped the tears from the corners of his eyes and asked inexplicably.

Yu Dong pondered for a moment, and then said slowly: "Lethe River is originally a river in the Netherworld. However, the bridge is suspended above the Lethe River.

When the dead soul crossed the Nai He Bridge, all the past and old things were written off. Therefore, in the water of the Lechuan River under the bridge, there are too many reluctance and attachment, regret and unwillingness of the souls. That's why Lethe River is called bitter water. Walking on the Nai Ho Bridge and crossing the Lethe River will remind the dead of all the sorrows and troubles of the past and present lives, so all the sorrows and sufferings carried by the Lethe River are the sorrows of the soul.

And the Lethe River in front of us can also make people have that illusion. This is the real reason why it is called Lethe. ”

Thinking about Yudong's words, it seems that this is really the case. Qin Zhen and Gu Jie were originally curious about the wonder of the water flowing upstream, but after admiring it by the stream for a while, they didn't know why, but unconsciously, an indescribable sadness began to swell up in their hearts.

Originally...... This qiē turned out to be caused by the stream! Qin Zhen was very surprised at this time and asked Yu Dong: "Even if there is a problem with that water, none of us have ever drunk that water!" How could it be that you got on the road?! ”

Yuto took a deep breath and took a deep breath, as if he was savoring the ingredients in the air around him. After a while, he frowned and said slowly: "This fourfold heaven is too powerful...... If we are not careful, we will all end up dying in the illusion we have created. ”

"Illusions?! I said Dong Shao, don't just scare people, to be clear! Gu Jie said eagerly.

As he continued along the road with them, Yuto said in a deep voice, "The water in this Lethe River has a subtle chemical reaction with the trees and leaves here. It causes the brain to secrete more dopamine.

Perhaps the dopamine of this kind of process dù will make people excited, excited, and happy at most. However, due to the Demon Lord's sorcery instigation, this slight reaction was magnified a thousand times. As a result, the effect changed from happiness to happiness and sorrow......"

Qin Zhen looked at Yu Dong in disbelief, he couldn't understand at all, what was wrong with this demon lord being a chemist? In order to create this Nine Heavens, he is really unscrupulous! But what Qin Zhen didn't understand the most was ...... What is dopamine?

Qin Zhen told Yu Dong the question in his heart, and Yu Dong also gave a very clear and clear explanation.

There are hundreds of billions of nerve cells in the human brain. However, there are some small gaps between cells. The information we receive has to jump through those gaps through the synapses so that the message can be communicated. The synapse releases a chemical that contains dopamine.

Dopamine can control human emotions, feelings, desires, and so on. Nowhere is it more evident than in love. The secretion of dopamine can completely make people crazy and not see any shortcomings in the other side. The so-called disregard for the promise of life and death is entirely caused by this neurotransmitter. That's why people have the illusion of having no regrets and being fascinated by the authorities.

The substance itself is also beneficial, as it can at least resist diseases such as depression. However, if the secretion is excessive and large, the result will be extremely counterproductive. That is to say, love will change from happiness to misery, from endless lust to pessimism and misanthropy.

In Yuto's words, during these four days, the dopamine secretion in the brain will exceed the normal situation by 5,000 times! 5,000 times...... That will have the effect of injecting a large amount of drugs, making people hallucinate in extreme ways! There are two types of hallucinations: either the one you want to see the most, the one you are most attached to; Either that's the last thing you want to see, the one you're most afraid of happening.

Because of the information transmitted by the brain, the person will not see the truth. Thus struggling between reality and illusion. If you don't have enough concentration and can't escape the illusion, it will be a dead end in the end.

In other words, the biggest enemy of these four heavens is not demons and monsters, not witchcraft and occultism, but himself.

It's their own hearts and demons.

(PS: Although this festival has nothing to do with me, but in order to respect the traditional Chinese festival...... And also to show my envy and jealousy for all of you...... Ahem, that ...... I wish all book friends who have a companion a happy Chinese Valentine's Day! As for the book friends who don't have a companion...... Just tie the villain with me, and I wish there are lovers in the world to get together and disperse...... OH,NO！ It is the end of the family, the end of the family...... ）