"It seems we won't reach an agreement."
"Sigh. In that case, we'll take our leave now. Someday, fate might bring us together again."
Gu Yu sighed and turned around, ready to walk out with Xiaozhai.
Sima Che sat on a chair, his eyes darting swiftly around. They had just finished another round of negotiation, which was to no avail. They wanted to see the Thunder Technique, but were unwilling to swap it for the Essence-consuming Method. He himself actually needed the exchange more than they did.
The wearer knew where the shoe pinched. Now that Tianshan Sect was passed down to him, the only thing left was the Heel-pressing Technique. It was the ideal manual to lay a foundation and one could cultivate with it up to the innate state. What would happen after the state was reached? There was not one word on that!
By contrast, the Essence-consuming Method was widely adopted by immortals of the ancient time. Words had it that it could support a cultivator up to the Human Immortal state.
Having devoted himself to cultivation for the past thirty years, even his dreams were about immortality and transcending to heaven. Now that the hope to realize his dreams was at his grasp, how could he miss a chance like this?
Our young duo did such a nice job in their little two-man act that Sima was convinced that they were not all that interested in the Thunder Technique. Seeing that they had risen to their feet, he could not help but said, "Please don't leave so soon!" 
"Anything else?" Gu Yu turned around.
"The Essence-consuming Method is such a unique piece of legacy that I completely understand your unwillingness to show it to others."
An idea came to Sima Che's head that instant and he grinned, "How about this? There is something that has been bothering me. If you could help me solve it, I'll show you the Thunder Technique all the same. How does that sound?"
"It sounds plausible, but we need to know exactly what your problem is first."
"Certainly. Please follow me."
With that, he led the two out of the house to the easternmost end of the secluded valley, then meandering up along a ridge.
The ground of the ridge was not paved and there was a narrow path trodden out after long years of use. They kept walking for a very long time, until the greenery faded out, replaced gradually by ice and snow. When they looked down again, the valley was tiny underneath.
They then climbed up another slope and stopped at it top.
'So here it is!'
Gu Yu realized with a kind of dull shock. He had sensed a suppressed sort of spiritual essence the moment he entered the valley, as if something was blocking it, and he had been looking for it ever since.
Once up here, they now saw a small moraine-dammed lake below the slope. A so-called moraine-dammed lake was formed when a glacier melted and r
eceded on it edge, leaving behind debris which piled up and formed a depression, partially blocking a riverbed.
The frosty-looking lake was as smooth as a clear mirror, a layer of white mist hanging over it, too dense to disperse. Bare black rocks surrounded the lake, which were made of partially stone and partially jade.
What surprised him the most, however, was a widespread of fluctuation created by the spiritual essence coming out of the lake, which was ready to gush out, but was suppressed by something even more powerful.
The spiritual essence was the product of nature and a purest form of energy on its own. Current scientific equipment could not even detect it, let alone pin it down.
'Damn, what the hell is in this lake?'
None of the excitement and flutter inside him was detectable from the indifferent look on his face. Sima Che had not a clue of what was going on in Gu Yu's head and asked, "Fellow Daoist Gu, what do you think of this place?"
"This natural creation is indeed extraordinary."
"You want me to go down there and have a look," grinned Gu Yu.
"Haha, I knew you were the right people for this job!"
Sima Che laughed. "To tell you the truth, this valley is the secluded cultivation site of my sect and this lake is the most valuable existence of the entire valley. According to the records of my sect, Patriarch Sa used to live in seclusion here to meditate on profound philosophical questions and left behind a most precious treasure. Sect seniors of the past had carried out multiple explorations of the area, which were all to no avail. However, starting from several years ago, I have been vaguely sensing something weird going on in the lake and the mist also rose up, as if the lake was haunted. I thought about going down and check it, but was held back by my limited capability."
Gu Yu frowned slightly. "This is the treasured site of you sect. Won't it be inappropriate for an outsider like me to nose around?"
"With the declining of the Taoist community nowadays, we should abandon our prejudices more than ever and work together with sincerity. Fellow Daoist Gu has achieved the innate state and maybe you will be able to find a clue. If there really were some rare treasure down there, wouldn't it be a reckless waste of God's creation to have it sinking there and wasting away?"
The brief lecture had covered everything from major principles to careful little thoughts, making it almost irrefutable. However, the better it sounded, the more hypocritical it felt.
Xiaozhai gave Gu Yu a look and shook her head inconspicuously. She would not assume the worst out of people, but neither would she assume the best. It was just that when a thing could not be explained by normal reasoning, there must be something fishy about it.
Gu Yu held his head low, as if deep in thoughts, while his mind was all over another matter—he was right, Sima Che could faintly detect the spiritual essence, although the man could not grasp the exact idea and depended greatly on his speculation.
The raw material of that jade plate was probably dug out somewhere around here.
Seeing that the duo both kept their silence, an eager look flashed across Sima Che's face. "Fellow Daoist Gu, what do you think?"
"I'm ok with diving in, but there's some information I need to know beforehand. Let's go back and talk it through."
Let's trace back to eight hundred years ago when Sa Shoujian travelled to Tianshan and co-founded Tianshan Sect with Yang Yantian.
The Yang Family had established themselves in this place and naturally attached great importance to the sect, but not for Sa Shoujian, who was merely passing through. Sa left the area after living here for a few years and went on with his travelling. In his old age, he traveled all the way to Fujian, which was almost the southernmost corner of the country, and was said to achieve enlightenment there and become immortal.
The so-called most precious treasure was probably not left there on purpose for the later generations to find, but a mere creation at a whim, which was played with before being tossed into the lake.
Tianshan Sect had gone through five dynasties and men had been salvaging for it throughout the ages with the hope of obtaining it and laying foundation to achieve the Great Dao. By the time Sima Che took over, he also dived in after detecting the abnormality in the lake. However, he never managed to pass the first two meters.
According to him, the lake water was of an extremely high density, resulting in exceptional buoyancy. He was exhausted shortly after diving in. It was indeed frightening.
"The lake must be a node of the spiritual essence. That thing should be a genuine piece, for it could lock in the spiritual essence tightly without letting out a single streak."
Inside the valley, Gu Yu spread out his mental force in case Sima Che was eavesdropping, and explained to Xiaozhai.
"He wants the treasure for himself and we become hard labor?"
"We'll exchange. As long as he can show us the Thunder Technique, I have no problem giving him a hand."
"Ha, I hope he's not bluffing."
They put the rope into order, adjusted their clothing and made preparation for going into the water. Sima Che was in his room the whole time. They had no idea what he was busying himself with.
They met again in the afternoon when Sima Che came out holding a wooden box. He smiled, "I have written down the Thunder Technique on a scroll and put it in this box. Don't worry, I will keep my promise."
Gu Yu scanned it with his mental force. There was indeed a scroll of paper with words on it inside the box, which looked like a manual of some sort. He frowned slightly, then unknotted his eyebrows with a smile, "I hope so."
The three of them returned to the lake. Gu Yu tied a rope around his waist and the other end was tied on a big rock with Xiaozhai watching over it.
Standing on the blue-black rock, he leapt out and dived into the lake with a flop.
The moment he hit the water, an unbearable freezing sensation wrapped around him from all sides, seeping forcibly into his bones. He circulated his spiritual essence frantically, and it ran through his body and counteracted much of the coldness.
Bai Town had plenty of brooks and he had been playing in them ever since he was little, making him quite a good swimmer. However, the density and buoyancy of the water here were both abnormal. A single wade that would normally carry him out for a few meters could barely move his body at all here.
It was like swimming in a giant blob of jelly. The deeper he dived in, the more difficult it became. He was wearing out only three to five meters in and he moved quickly back, pulling the rope at the same time.
Seeing the sway of the rope, Xiaozhai pulled with all her strength and Gu Yu's head popped out of the surface with a splash.
A campfire had been set up beforehand and Gu Yu warmed himself up by it. Sima Che asked in a hurry, "Fellow Daoist Gu, how are you feeling?"
"I'm all right, just need to rest a little."
"What's in the lake?"
"I have no idea yet. I was only able to go down for three to five meters before coming up."
"According to my master, the seniors were able to dive very deep into the lake, but still found nothing. It was after the white mist showed up that the water started to go weird. If you find it too much of a trouble, then…"
"That's ok, I'll try again later."
After a brief rest, Gu Yu returned to the water with a series of experiments by entering the lake at different spots. Gradually, he grew used to the environment in the lake and was able to dive deeper down each time.
By the time he was in for the fifth time, the sunlight was fading.
The sound of water characteristic to this lake sang into his ears. Broken pieces of ice surrounded him, glistening with a dim blue light. The buoyancy grew stronger deeper down. After a few vigorous dashing-down, Gu Yu finally made it all the way to the bottom of the lake.
The scene was not something he had expected. Instead of bare ground, the bottom of the lake was covered by strange, unknown water weeds. The verdant plants intertwined and swayed, reminding one of ancient remains abandoned by time. It was a soundless and eerie scene.
All of a sudden, an unusual fluctuation disturbed his mental force and disappeared in the blink of an eye.
Gu Yu opened his eyes widely and swam towards the direction it came from, his heart thumping loudly. If he sensed it correctly, he had experienced similar fluctuations before—from none other than the fishbone from Wudao River!
We need not elaborate further on the meaning on that fishbone: the incomplete Essence-consuming Method, the vision-conjuring skill, the anecdote and travel notes… it had laid the foundation of his cultivation road.
This thing here, however, just happened to be on top of a node and suppress the spiritual essence for some reason.
What could be in there?
Almost instantaneously, a thought that frightened him came into his head, which he shook off right away.
He brushed aside the curtain of water weeds with much difficulty. Gu Yu fumbled around with his hands for a long while before discovering that thing.
It was a palm-sized black object, almost as inconspicuous as a square stone. On top of it carved something resembling a dragon with gaps on its body, which was used as a handle.
This... should be an ancient seal.
Gu Yu paused briefly, then refocused his eyes and grabbed the body of the dragon. He pulled.
It did not budge.
With more strength, he pulled again.
The sound of flowing water grew louder abruptly, almost like rumbling thunder now.
He dared not tarry. Concentrating the spiritual essence on his right hand, he lifted for the third time.
Sheets of water weeds were cut in half at mid-length, as if being neatly reaped by a gust of wind. A blast of air spewed out from beneath the ancient seal, instantaneously gashing open the lake bottom. The flow of water had transformed into large drops of water, which rolled around Gu Yu.
The dense and chaotic spiritual essence was visible to the naked eye. In the form of white marks, they slashed frantically into the entire moraine-dammed lake.
A drop of water knocked into Gu Yu like a cannonball, which he failed to dodge. The impact sent him into a backflip. He barely managed to steady himself and realized the situation did not look good for him. Carrying the ancient seal in his hand, he swam upwards.
On the bank, Xiaozhai watched as the lake burst into life. One moment it was all peace and quiet and next moment, all hell broke loose.
She acted before she could think and wrangled with the rope, which was tossed around under the impact, making it impossible for her to hold on. She shouted, "Need a hand here!"
Sima Che was still playing the onlooker and only came to her aid after her calling.
With both of them at the rope, it was finally pulled out of the water a little bit at a time. Several breaths later, a figure flew out and landed ashore. A series of loud bang followed him, as if something was exploding.
Gu Yu landed on all fours, gasping for air. After wandering around for all this time, it was the first time he felt a danger at this level.
Sima Che was the first to come to himself. He flung himself over in large strides and grabbed the ancient seal.
He looked closely at it for a moment, his face taken over by interchanging crying and laughter. His hoarse voice said, "The Seal of Patriarch Sa, it's the Seal of Patriarch Sa… Master was telling the truth, sob…"
Seeing Sima possessed by this frantic state and crumpled to the ground without moving, Gu Yu yelled at him, "It's not safe here! We need to move! Now!"
Barely did he finish that sentence when a deafening sound came from within the lake. Half of the water was in the air, then poured down as if Milky Way itself was dumped out. Instantly, the hundred-square-meter area was drenched.
Immediately after that, thunder rumbled above, as if bolts of lightning were striking down from all heavens.
The sound was so magnificent that even Sima Che was awakened from the trance. The three of them raised their heads in unison and let out a sigh: we're finished!
 TL/N: the two-man act, or 双簧, is a type of comic show with one speaking or singing while hiding behind the other who does the acting. Of course, the term is metaphoric here, on the duo's singing to each other's tune.