It seems that because of the existence of the tree insect group, it is difficult for him to break through the square above ground.

After weighing it in his heart, Xuanyuan finally returned to the underground space, intending to make a decision after exploring the underground space first.

As mentioned before, tail fans generally live in underground rivers. Since there is a tail fan in the lake, this also means that there must be a passage in the lake that can lead to the underground dark river, and Xuanyuan can return to the surface along the dark river below.

However, the troublesome thing is that most of the terrain of the Dark River is very complicated, and it is not easy to find a way out from it.

It is important to know that each river has its own supply and drainage channels, and what is even more difficult is that each river has a different distribution pattern.

It may be dendritic, jagged, linear, reticulated, ...... Moreover, dark rivers with different distribution states may even intertwine with each other to form a more complex underground dark river system.

If you're not careful, you can get lost.

Walking to the lake, Xuan Yuan took off his outer robe and wore only a tight-fitting cloth shirt on his body. Subsequently, Xuanyuan successively removed some sundries from his body.

Looking at the "Heart Refining Sword Sutra" in his hand, Xuan Yuan finally kept it for future beginner disciples to use.

After all, although the White Dao Sword was shattered by the impact of the Three Treasures Ruyi, the charm of the visualization map did not completely dissipate.

At this moment, turning the pages of the book and looking at the blurred visualization map on the paper, Xuan Yuan could still feel a chilling sword intent from it—of course, it must be weaker than before.

However, even so, this visualization map, which is a lot more blurry, can still be quite effective in sharpening the divine consciousness for most people below the first realm.

Carefully placing the Heart Refining Sword Sutra on the folded robe, in the end, all that was left on Xuan Yuan's body was a Frost Descending Magic Sword, two Earth Spring Fruits, and a large bag of grass seeds collected from around the tree house.

Taking a deep breath, Xuanyuan jumped into the lake.

The lake water was far colder than Xuanyuan imagined, and as soon as he entered the water, a large amount of ice seemed to be piled up around him, and the cold air irritated the skin on the surface of the body pervasively.

Xuanyuan did not change color, but tried his best to calm his mind and feel the flow of water under the lake. Without much effort, Xuanyuan found something.

Swimming against the current, Xuanyuan came to the easternmost part of the lake, and looked at the large piece of limestone piled up and precipitated under the rock wall, Xuanyuan's eyes lit up.

Because the karst caves and underground passages where the dark river is located are mostly accompanied by lava reactions, the water flow of the dark river generally carries a lot of limestone powder.

The large limestone in front of you is likely to have accumulated over the years as the underground river flows into the lake.

Pushing aside the lush aquatic plants, Xuanyuan found a dark river channel with a diameter of about two meters at the rock wall.

Finding the target and jumping out of the water suddenly, Xuan Yuan rubbed his eyes that were a little uncomfortable because he had been open in the water, and let out a long breath.

Knocking down a glowing stone from the rock wall, Genyuan plans to dive into the water again and explore the passage.

However, after knocking down a glowing stone, Xuan Yuan accidentally glanced at it, and his expression couldn't help but be stunned: where is this glowing thing, what kind of stone is it, it turns out to be amber wrapped in butterflies!

In the fist-sized transparent amber, a butterfly about the size of a coin lies silently in it. However, the dazzling light emitted by the wings that were one or two centimeters long actually illuminated the area of two or three meters around Xuanyuan as if it were brightly lit.

Even, when Xuan Yuan looked closely, he also found that in the very center of the light, there was still a little bright yellow color.

Raising his head, Xuan Yuan looked at the large and small luminous objects on the stone wall, and a look of surprise flashed on his face, could these all be butterfly amber?

Xuanyuan's magic trick pinched, rode the wind from the surface of the lake, climbed to the rock wall in mid-air and carefully observed. In fact, Xuanyuan's guess was indeed correct, all the luminous objects were amber wrapped in butterflies.

Falling from the rock wall in mid-air, Xuan Yuan squeezed the luminous body in his hand hard, but the amber was unscathed. Even if a blue air fire was summoned, it would not be able to consume it in the slightest.

So hard? Xuan Yuan felt that he was becoming more and more unable to understand the remains of the Seventh Hidden Vein, and all kinds of strange things were emerging one after another.

The first thing to do is to get out of here as soon as possible!

The idea became more and more firm, taking a deep breath, Xuan Yuan focused his attention, took out a grass seed and threw it into the sky, the grass seed turned into a grass whip in the wind, and it soared to a length of more than ten meters in just an instant.

As soon as the seal changed, Xuanyuan controlled the dark river passage that it drilled into the rock wall.

Twists and turns, uneven, relying on the faint connection, Xuanyuan roughly perceived the topography of the dark river channel.

Ten meters, twenty meters, thirty meters...... Slowly groping, the whip has almost extended to more than a hundred meters!

However, the water pressure that Xuan Yuan sensed from the straw whip still did not change significantly, and the two grass whips were still below the surface of the water—that is, the two-hundred-meter passage was all filled with water.

This is not good news, the three little ones can't support themselves after staying underwater for a long time without being fed by air.

The straw whip continued to extend, almost two hundred meters long, and at this moment, the green light on its body was no longer visible! From time to time, there were a few subtle "click" sounds on the grass whip, which also implied that it had reached the limit of its length.

Suddenly, the whip seemed to break through the water surface and into the air, and the water pressure from the surface suddenly decreased!

However, it is unknown whether the whip suffered from some accident or because it had stretched for nearly two hundred meters and could not withstand the pressure, and the moment the pressure was reduced, it suddenly broke apart.

Even, Xuan Yuan didn't have time to perceive its details.

Frowning, Xuan Yuan finally took a deep breath, holding the glowing butterfly amber in one hand and the frost descending magic sword in the other, and dived into the dark river passage on the rock wall.

Straight ahead, right, left, left, right, right, right...... Transporting the Wind Riding Method, relying on the experience he had tried to find out with the straw whip before, Xuanyuan accurately headed towards the destination.

Sparing the raised rock walls and rocks, avoiding the sunken soft mud ground everywhere, Xuanyuan is like a flying fish, quickly shuttling through the dark river channel.

In about half a minute, the water level in the passage finally lowered, just to the point of Xuanyuan's nose, however, the water became more and more rapid, and even Xuanyuan had to reduce his speed to ensure that he was not injured by the raised stones.

As he got closer and closer to the entrance of the passage, the sound from the front became louder and louder, Xuanyuan's expression froze, and a ridiculous thought flashed in his mind.

Without hesitation, Xuan Yuan took out his magic sword and thrust it into the rock wall beside him, and with this resistance, he could stop at the end of the passage.