As he spoke, the volcano on the lower left suddenly shook, and a puff of white smoke emerged from the crater. The smoke seemed to be heavy, and it did not rise upwards, but flowed down the hillside, heading straight for the place where the elixir grew. Then, another volcano on the right also sent out a shock, and the same puff of smoke flowed here. The smoke from the volcano on the right is pale red, which makes it look even more eerie.

When these two puffs of smoke just came out, Tian Xu's olfactory imaging had already given the answer: the white smoke that came out first on the left was nothing, mainly water vapor and some harmless substances mixed in it, which was formed by the condensation of cold air outside after emerging from the crater, similar to ordinary fog, and basically harmless.

The red gas on the right contains strong corrosive substances, and it is extremely toxic, this toxicity may not matter to plants, but for higher animals, it is extremely powerful, it can be said to be immediately killed.

Now Tian Xu understands that there are such highly toxic substances emitted here from time to time, no wonder birds refuse to come here to perch. However, there is another point that makes Tian Xu wonder: if such poison often appears here, why can't it be detected in the soil, in the air, and in the nearby seawater?

Thinking about this question in his heart, he didn't pause at all, pulling the purple smoke and flying directly from the same place more than a hundred meters high, letting two streams of fog flow under his feet. Then he saw another strange sight.

The white mist arrived first and soon covered the saddle where this plant grew. Then, the red mist also arrived, and the two mist met right at the edge of the plant growth on the right slope, and after the confluence, the two mists merged together to form a strange pink.

This pink begins on the right side and gradually spreads to the left, reaching the edge of the plant growth on the left, and then no longer flowing farther away, at this time, the fog from the crater on both sides has also stopped, and only the place where the plants grow is shrouded in this pink mist.

Tian Xu's olfactory imaging was activated with all his strength, and he carefully observed this pink mist, and found that after fusing with the white mist, the toxicity in the red mist that came out on the right had basically disappeared, as if there had been some chemical change and turned into another non-toxic substance.

Tian Xu carefully distinguished this substance, but he didn't know what it was. And this pink mist did not possess aura or other substances beneficial to plant growth as he had imagined. He was even more confused.

When Tian Xu started, because he was worried about the toxicity in the red mist, the olfactory imaging did not penetrate deep into the mist. It's not that his olfactory imaging is fragile, it's that he doesn't want to take too many risks. At this time, when the observation was fruitless, he directly penetrated into the fog to feel the characteristics of the fog.

The thickness of the fog accumulated on the hillside was not large, only more than two meters, and after the olfactory imaging entered, it was quickly possible to see the plants that were shrouded in it. The plants swayed slightly under the mist, as if they were very excited.

However, Tian Xu's olfactory imaging showed that the plants did not absorb the mist.

"What's going on?" Tian Xu thought strangely, "Could it be that these mist really aren't the reason why these plants are nourished?"

His olfactory imaging and domain were activated at the same time, and after examining the inside of the plants, he discovered that the secret was in the underground where the plants grew. Streams of aura were concentrating from the ground into the mist-shrouded area, and then absorbed by the plants.

His spiritual realm was concentrated on the mist again, and he finally found that these mist were emitting a very slight vibration, forming a force field aimed at the underground aura, attracting the underground aura to converge here, like a trickle, providing aura to the plants on the ground.

These mist actually formed a special set of spirit gathering arrays.

"Could this mist be a spiritual substance, and who gave it a formation?" Tian Xu became more and more curious, and carefully studied the formation in the mist.

Although the fog is constantly surging without any regularity, the fog molecules themselves are vibrating in multiple bands at the same time. Due to the very large total number of fog molecules, there will always be a resonance of the vibrations of some molecules at some point, and then this resonance will have an attraction to the aura underground.

However, this vibration of the mist seems to be only useful for the aura underground, but it is of little use for the aura in the air that is not too rare, which is another characteristic that makes Tian Xu strange.

Those aura molecules that come from the ground seem to have similar multi-band vibrations, which attract each other to the fog molecules. This kind of vibration was accurately captured by Tian Xu's spiritual realm, and while they vibrate, they were also releasing an electromagnetic wave, and it was the existence of electromagnetic waves that caused the two completely different substances of mist and aura to attract each other.

Tian Xu's olfactory image is blocked by the earth, and he can't go deep into the ground, and he can only vaguely feel the situation at a depth of several meters, which is not very clear. However, his spiritual realm is a transcendent existence, which will not be affected by the sea or the earth, and can completely explore and control dozens of meters underground.

Although his probing depth was not too deep, it was enough to find the pattern of these aura, because these auras had obvious regularity at a depth of more than thirty meters underground, and they came from the northwest direction.

This gourd-shaped twin volcanic island is northeast to southwest, and the northwest direction is exactly across the gourd's thin waist, and there is no volcano on either side of the block, so it is quite easy to trace the source of the aura.

The island chain of the Kuril Islands stretches roughly from southwest to northeast, with the Sea of Okhotsk to the northwest and the vast Pacific Ocean to the southeast. From this point of view, these auras should come from the inland sea of the Okhotsk Sea, compared to the vast and deep Pacific Ocean, Tian Xu's confidence in this direction is much stronger.

Since going to sea this time, after facing the Shizhi Idea on Putuoshan Island and the mirage in the deep sea of the Sea of Japan, Tian Xu began to calm down with some pride on the land, he already understood that on this earth, a group of self-righteous Ning Dan Realm cultivators in the cultivation world, as well as several Earth Immortal level cultivators he had seen, were not the most powerful existences, far from them. Since there is such a powerful existence in the marginal sea, then in the middle of the ocean, God knows what level of demon will appear, with a small Ning Dan realm like him, he will definitely not be able to fight head-on.

After saying hello to Ziyan, Tian Xu took the lead in diving to the bottom of the sea and swam in the direction of the source of the aura on the seabed. Ziyan didn't know what Tian Xu had discovered, she had absolute confidence in Tian Xu, since Tian Xu was exploring the past in this direction, she didn't ask much, and followed Tian Xu to the bottom of the sea.

The depth of the seabed along this road is not large, ranging from tens of meters to two or three hundred meters. The spiritual flow under the water is very weak, and sometimes it is intermittent, and the scope of Tian Xu's spiritual realm is relatively small, and it is still difficult to track. Fortunately, the distance that needed to be tracked was not too far, and more than seventy kilometers away, a small submarine volcanic island appeared in front of the two of them.

This volcanic island rises abruptly from a flat seabed less than 200 meters deep, and is almost a standard cone, not very high, and more than 30 meters above the sea. More than thirty meters does not seem to be deep, but it is enough for all the current human ships to pass safely from above, and its size is so small that it is very unobtrusive. And the spiritual flow that Tian Xu tracked all the way flowed from the bottom of this small submarine volcano.

It's just that although this volcano is small, the diameter of the bottom is more than three hundred meters, Tian Xu's domain can only detect about fifty meters, and it is completely impossible to penetrate it, so he can't know where the aura inside this small volcano comes from, which makes him feel very frustrated.

Tian Xu swam around the bottom of the volcano, although he still couldn't see through the scene inside the volcano, he found some special features of this volcano, as well as some laws of the flow of spiritual energy inside the volcano.

Inside the volcano, the aura should have flowed slowly from top to bottom, and when it reached the bottom, it changed direction and headed towards the strange gourd island seventy kilometers away. Tian Xu carried out olfactory imaging and found that the aura in the nearby sea was slowly converging towards the top of the volcano. In other words, this small submarine volcano should be a special gathering array.

Tian Xu observed around this undersea volcano, and his hard work paid off, and he finally found the secret of this volcano.

The volcano starts at the base and has three normal lines spiraling along its outer surface, eventually converging at its top. These three formations can each emit electromagnetic waves into the interior of the volcano, which has an effect on the aura. This effect is somewhat similar to that of a typical transformer or electromagnet, where the spiral forms a hollow solenoid inside the volcano, causing it to form a special electromagnetic field. The functions of the three spirals are different.

One of them uses the volcanic body as an antenna, emitting a special electromagnetic field signal from the top of the mountain to the surrounding area, which can form an attraction to the surrounding aura, attracting the aura to condense near the top of this submarine volcano and eventually enter the mountain.

The other one paints a special imprint on these auras, giving them a special vibration frequency, so that they can echo the fog on the gourd-shaped island in the distance, and can be teleported to the island.