The Sixteen-Character Esoteric Art of Yin-Yang Feng Shui, though titled as sixteen characters, could more accurately be described as sixteen chapters, each represented by a single character, totaling sixteen characters—hence the name. These sixteen characters are "Heaven, Earth, Man, Ghost, God, Buddha, Demon, Beast, Awe, Suppress, Flee, Object, Transform, Yin, Yang, Void." Each character is a unique symbol in ancient divination mathematics, signifying "Time, Space, Matter, Life." When combined, they generate specific "Trigrams" from which one can interpret fortune, disaster, and the past and future.

This seminal text, primarily documenting Yin-Yang Feng Shui, is truly comprehensive. Not only does it contain arts of Feng Shui and Yin-Yang, but because it was authored by masters of the Mojin Xiaowei (Grave Robbers), it also covers descriptions of the forms, structures, and layouts of ancient tombs across various dynasties. Its principles are entirely derived from the Sixteen Innate Trigrams evolved by King Wen of Zhou. The jade divination disk beneath the iron tree in the water is precisely such a "divination plate," using various mathematical figures like "Time, Space, Matter" to deduce "Trigrams."

Years ago, the excavation of an ancient artifact in China caused a sensation: the bronze esoteric object, the "Taiyi Nine Palaces Divination Plate," unearthed at Shuangguidi, Fuyang County, Anhui. Many speculated about its function; in reality, it was a precise instrument used in ancient times to deduce the mathematics of Trigrams. However, the range of numbers it could deduce pales in comparison to the jade disk we have found. This jade disk is made of Vajra Jade, buried deep on the seabed. It is light red, transparent as glass, pure, and flawless, untouched by the corrosive salts and acids of the seawater. Although called jade, Vajra Jade is neither nephrite nor jadeite. The ancients called jade the fairest of stones, often found near the foothills of Kunlun Mountains, mingling with sand and gravel at river bottoms, prized for its warm, fine texture and fatty luster. There is a distinction between soft jade (nephrite, where pure milky white is valued) and hard jade (jadeite, which is more resistant to dissolution and typically bright green). Vajra Jade possesses the beauty of nephrite while surpassing the quality of jadeite, making it an anomaly among stones, its hardness approaching that of crystal, though less than gemstones, and exceedingly rare in China. Moreover, the conception of this jade disk held by the bronze figure is exquisitely intricate. Through the Six Pillars and Three Patterns at the base, it can generate infinite mathematical figures, harboring mysteries far beyond the comprehension of ordinary people.

For many preceding years, I had yearned for an opportunity to glimpse the complete Sixteen-Character Esoteric Art of Yin-Yang Feng Shui. But now, holding the divination disk in my hand, I began to understand that even possessing the complete form of the Sixteen Trigrams, with my half-baked, superficial knowledge, I was utterly incapable of deciphering the heavenly secrets it contained. Perhaps I had overestimated my own abilities before. Now, fully aware that I needed the disk to display the Trigram of "Zhen Upper, Zhen Lower" (Zhen Gua), I found myself completely at a loss before the complex and vast Taiyi mathematical figures, unsure where to even begin. I could only shake my head in frustration at Shirley Yang, realizing we needed another approach.

Unexpectedly, Gu Cai suddenly stepped forward, volunteering to attempt to deduce the Trigram on the plate, specifically the Zhen Gua, which is comprised of one Yang line and two Yin lines. None of us, including myself, ever imagined he possessed knowledge of this field. We were all startled and skeptical, completely unable to believe such words could emerge from the mouth of this Danzai (boat-dweller).

After a moment, the others gradually regained their senses. Uncle Ming turned to Gu Cai, saying, "Danzai, how do you know the Innate Trigram numbers? Our lives depend on this now; this is no time for jokes. What exactly..."

Before Uncle Ming could finish, Fatty interjected, "Specialized tasks require specialized skills. When it comes to solving puzzles and reading Trigrams, we rely on Old Hu's expertise. His ancestors ate from this bowl. Besides, truth is always held by the minority, not just anyone with a head on their shoulders can grasp it. You, a mere fisherman’s boy, shouldn't butt in; otherwise, if you jeopardize everyone’s lives, you won't be able to bear the responsibility. Do you know how much a life like mine is worth per pound, kid?"

Gu Cai looked even more bewildered by the remarks from Uncle Ming and Fatty. His already meager confidence evaporated, and he stammered, unable to articulate a clear sentence.

Seeing his state, something stirred sharply within me. I suddenly realized that the ancestors of the Danyun people were the very masters of this Guixu ruins. Lord Hen Tian obsessed over Trigram mathematics—could these ancient secrets have been preserved among the Dragon Families (Long Hu) and Otter Families (Ta Jia)? I had to press Gu Cai for clarity: how could an orphan isolated on a desolate island utter something like, "Zhen corresponds to one Yang and two Yins?"

With this thought, I quickly addressed the group, "Don't jump to conclusions just yet. Is truth always held by the minority? Of course not. However, truth is sometimes indeed confined to a select few. Since the Danyun people managed to pass down the Tou Hai Tu (Underwater Navigation Map) tattooed on their bodies for thousands of years, it is entirely possible they also know about the Innate Trigram numbers. We might as well let Gu Cai try."

Shirley Yang placed the Vajra Jade disk into Gu Cai's hands. Knowing he was inarticulate, she told him not to overthink it, just to try his best. Duo Ling, uncertain what "Trigram mathematics" Gu Cai understood, repeatedly urged him not to mess around.

Gu Cai stared intently at the various symbols on the three pillars of profound mechanism, as if recalling long-dormant knowledge that required deep mental strain to retrieve. The numbers in Guixu did not contain the "Complete Sixteen Heaven Trigrams." Legend has it that the "Eight Innate Trigrams" were created by Fuxi, also known as the "Fuxi Innate Eight Trigrams Diagram." The "Eight Acquired Trigrams" were developed by King Wen of Zhou based on the Nine Palaces numbers derived from the He Tu and Luo Shu. King Wen, possessing divine insight, merged and deduced the Innate Eight Trigrams and the Acquired Eight Trigrams on tortoise shells, exhaustively exploring the transformations of Heaven and Earth to derive the "Complete Sixteen Heaven Trigrams" that concealed heavenly mechanisms.

The "Complete Sixteen Heaven Trigrams" ceased to exist by the late Western Zhou Dynasty. In the late Qing Dynasty, Mojin Xiaowei unexpectedly excavated the complete Trigram images from a Western Zhou tomb, leading to the compilation of the Sixteen-Character Esoteric Art of Yin-Yang Feng Shui. Because half of the book was destroyed, my knowledge is limited to the Feng Shui techniques; I barely understand the subtle variations of the Yin-Yang Trigrams. It was only in the last six months that I gradually started engaging with the Five Elements and Eight Gates. But the I Ching is the path of continuous change. Knowing only a fraction of it is practically equivalent to knowing nothing.

However, the moment Gu Cai blurted out the Zhen Gua corresponding to one Yang and two Yins, I knew he spoke with substance. Moreover, his knowledge seemed to belong to the "Innate Trigram numbers." Among the Eight Trigrams in the I Ching, divided into "Qian, Kan, Gen, Zhen, Kun, Dui, Li, Xun," arranging them by number yields "Qian One, Dui Two, Li Three, Zhen Four, Xun Five, Kan Six, Gen Seven, Kun Eight." Zhen occupies the fourth position, corresponding precisely to the fourth Trigram composed of "one Yang and two Yins." In the Acquired Eight Trigrams diagram, Zhen is in the third position, with the classic sequence being "Kan One, Kun Two, Zhen Three, Xun Four, Qian Six, Dui Seven, Gen Eight, Li Nine." This modern sequence, which relies on mathematical figures to represent the spiraling recurrence of spatio-temporal changes to calculate future events, is more commonly circulated today, but it is not the ancient method used to deduce Innate Trigrams.

I watched as Gu Cai rotated the Yin and Yang profound mechanisms one by one. Hundreds of sieve holes on the Vajra Jade disk immediately closed and shifted, the resulting mathematical figures gradually coalescing into the Trigram image. Everyone watched Gu Cai’s actions in confusion; only I could discern a hint of the method.

The Zhen Gua is the Trigram of one Yang and two Yins. The Yang number is Nine, the Yin number is Eight. Calculating based on its positional value of "Four": one Yang yields four times nine, thirty-six; one Yin yields four times eight, thirty-two; the second Yin also yields four times eight, thirty-two. Combined, they produce the number "One Hundred," giving rise to the "Hundred Li" mechanism within the Zhen Gua image.

As for how phrases like "Zhen arrives with a roar, laughed at with chattering" (Zhen lai kexi, xiaoyan ya ya) emerge from these derived numbers, I have no way of knowing. What I do know is that in the Innate Trigram system, the sums of corresponding pairs of Trigram numbers always equal Nine, the number of the greatest Yang, "Old Yang." Heaven is Yang, Earth is Yin. In the Acquired Eight Trigrams, the corresponding sums equal "Ten," depicting "Earth." The numbers Gu Cai deduced were mostly Old Yang celestial numbers. It seems the Trigrams reflect specific contexts, aligning with the hidden implication in the Zhen Gua that "the act of offering sacrifices to Heaven must not cease."

I couldn't help but exclaim to Gu Cai, "My man, you really have it! You can even deduce the Innate Trigram images." Hearing me say this, Gu Cai knew his method of deduction was correct. All this was taught to him orally by his father before he turned thirteen. It was said that these were ancient incantations Longhu and Tali lineage members learned from childhood, though they were thought to have no practical application. He never knew what those profound chants referred to in terms of Trigram mathematics. Now, they were proving so immensely useful; his mother and father, watching from above, would surely be comforted.

The Vajra Jade disk was layered, each level containing countless finger-thick holes, varying in size and distribution. As Gu Cai pushed out the numbers for the final pattern, certain holes across the multiple jade layers interconnected, arranging themselves into the marking for the Zhen Gua. The disk connected to the arms of the bronze figure. Suddenly, the internal mechanisms of the statue engaged with a dull thunk. From the holes filling the bronze figure—filled with copper sea sand—dozens of bronze shark heads emerged. These bronze Jiao (mythical sharks) were ferocious-looking, slightly thinner than a child's arm, all sculpted with their mouths agape as if holding a pearl, yet their mouths were completely empty.

When the others saw that Gu Cai had finally activated the mechanism on the Innate Divination Disk, they were about to cheer, but then they saw numerous shark heads protruding from the torso of the bronze statue that supported the disk with its four arms. Everyone froze, struck silent, staring fixedly at the empty bronze Jiao mouths, unable not to wonder: "What the hell are these things?"

I reached out and touched a shark mouth. The pitch-black sea sand inside possessed qualities of gathering copper and accumulating Yin, but brushing my hand across it, I couldn't feel any suction. The hollow grooves in the shark mouths were clearly designed to hold large South Sea pearls. I wondered aloud, "These... these gaping Jiao mouths seem designed to place the Dragon's Luster found in the sea..."

Shirley Yang commented, "The Nine-Legged Ding holds the marking of a lunar orb buried under an immortal mountain beneath the sea. The moon rises and falls with the tide. It seems we need to place the Dragon's Luster into the mouths of the Jiao dragons, sink the bronze figure at the underwater mechanism beneath the iron tree, and then the burial mountain under Guixu will split open, floating the zombies to the surface with the current. Is such a thing truly possible?"

Seeing a chance to escape, Uncle Ming quickly informed everyone that among those who harvested eggs from the waves, there wasn't a single person who didn't know the ancient legend of the moon buried in the underwater mountain graves. The moon is the essence of water; pearls are the essence of the moon. In essence, the luminous pearl is the moon. Vajra Jade is ancient sea jade; the pearl and jade correspond, so its radiance must be stronger than true moonlight. However, filling all the Jiao heads on this bronze figure would likely require scores of top-grade Dragon's Lusters. Duo Ling and Gu Cai nodded in agreement nearby, confirming Uncle Ming’s statement; the legend of the moon buried beneath the immortal mountain was widespread and known by every Danmin (boat dweller).

I gritted my teeth. It seemed I couldn't profit without taking a risk. We had no choice but to embed all the luminous pearls we collected from the coral spiral into the Jiao mouths, then sink the bronze figure to the mechanism beneath the iron tree at the seabed. As for whether this would cause the immortal mountain to crack and the sea to surge, bringing the zombies to the surface—only time would tell. It was currently unimaginable how a hundred or so pearls could bring about such a dramatic change.

Fatty quickly clutched the knapsack containing the moonlit luminous pearls: "Commander Hu, you can't be serious! So many fish mouths, how many do we have to feed them? I must emphasize again: corruption and waste are extremely serious crimes."

I told Fatty, "How is it a crime? The principle of the Mojin Xiaowei is to sacrifice wealth, not life. We are all people destined for great things in the future. If we can't get to America, all the Green Heads we acquire are meaningless. Besides, we still have the priceless mermaids and the Buddha’s Emerald Heavenly Robe. If we are frugal in America, we can live comfortably for half a lifetime."

Despite saying this, I couldn't help but look at the backpack holding the South Sea pearls and think: "After risking my life in the sea for half a day, I only managed to gather thirty-two luminous pearls. After Ruan Hei died, I placed one in his mouth as a 'Youth-Retaining Pearl.' Now I only have thirty-one left. Each one is the condensed essence of the South Sea Dragon's Qi. Anyone would ache to sink them all to the bottom of the sea. Moreover, the quantity is severely lacking; thirty-one luminous pearls are far from enough."

Shirley Yang placed a few pearls into the Jiao mouths. Sure enough, regardless of size, each bead was held tightly and securely by the shark head. But they needed at least sixty or so luminous pearls that could shine a hundred paces to fill every mouth. Shirley Yang couldn't help but shake her head repeatedly. The burial offerings of Lord Hen Tian were so lavish; perhaps even the tombs of Emperors Taizong or Zuzong of the Tang and Song dynasties didn't possess dozens of these South Sea essences. Where could we possibly gather over sixty luminous pearls now?

Gu Cai, noticing everyone's worried expressions, seemed to sense their concern over the insufficient South Sea pearls. He quickly pointed toward the water surface, gesturing toward the deep underwater ravine: "There's a Dragon Lair below!" Uncle Ming hurriedly asked for details, then relayed them to us. It turned out Gu Cai was from the Long Hu lineage among the ancient Danyun people. They possessed many innate skills in the sea, especially excelling at "judging water color and recognizing a Dragon’s Dwelling."

Earlier, Gu Cai had with me and Fatty beneath the coral tree where the Jiao sharks appeared. He saw a deep ravine at the bottom. Being skilled in reading water conditions, Gu Cai immediately noticed the abnormal swirling turbulence and knew there must be an ancient giant clam in the ravine. It was a "Mother-of-Pearl Sea," perpetually deprived of sunlight, likely harboring a Clam Ancestor. Sea mollusks differ from freshwater ones; ocean mollusks yield only one pearl per shell grouping, but the mother-of-pearl under the sea belongs to colossal creatures yielding a hundred pearls per shell grouping.

A Mother-of-Pearl shell might be ten times larger than a Chage (giant clam), found only deep within underwater caves and crevices. A sea area or pool that yields pearls exceptionally well must hide an ancient mother-of-pearl, known as the Clam Ancestor. Legend says the Mother-of-Pearl is an ancient clam that has transformed into a spirit over the ages. Because its shell envelops a hundred luminous pearls, even if the moonlight overhead is flowing like water, it remains hidden deep within the ravine and never emerges.

In ancient times, if a Dan person found subtle clues underwater and approached the vicinity of the Clam Ancestor, they often failed to discover the giant clam, which had merged seamlessly with the reef. Many were also deceived by its shifting forms and became food for the "Clam Spirit." The Clam Ancestor, hoarding numerous Dragon's Lusters hidden in the deep water, generates a significant amount of low-frequency pulses. While this has little impact on the human body, it severely interferes with all electronic signals. Shipwrecks and plane crashes in the Coral Spiral Sea area are often attributed not only to unpredictable weather and sea conditions but also to this hidden Mother-of-Pearl.

Initially, we hadn't paused to consider what the Dragon Skeleton might be. Although there are many records concerning Mother-of-Pearl, very few people have ever captured this spiritual creature; none have seen it for over a thousand years. Thus, from the beginning, we hadn't considered it. It was only when Gu Cai read the water color to recognize the Dragon's Dwelling—identifying the seabed as a "Mother-of-Pearl Sea"—that we understood the Dragon Skeleton tattooed on Gu Cai’s back via the Tou Hai Tu was actually the mark for a "Dragon Lair." The Dan people have always used "pearl" as a metaphor for the Dragon's Luster, and a sea with pearls is a "Dragon’s Dwelling."

The undercurrent near the whale bones was now completely still and silent, and the sense of chilling cold in the air intensified. After a brief discussion, everyone steeled their resolve. Since there was a "Mother-of-Pearl" that housed a hundred pearls per shell grouping in the deep ravine, we had no choice but to risk our lives again and descend to scrape the Dragon's Lusters from the shell of the Clam Ancestor. However, this task was extremely perilous because no one had ever captured this millennia-old giant clam before. It was said the Clam Ancestor, through ten thousand years of absorbing and refining energy, was adept at illusion and highly concealed, hidden beneath the currents and eddies of the deep ravine—a series of swirling vortices that made approaching it nearly impossible even at the cost of one's life.

As everyone struggled with the dilemma, Uncle Ming suddenly devised a plan. He retrieved several ancient esoteric artifacts from the spiral shell graves of the Guixu ruins, designed to lure dragons and slay clams. Among these was a Corpse Specter resembling a woman's skin pouch, which could serve as a pearl medium to lure the Clam Ancestor out from the seabed. However, strapping this eerily spectral Corpse Specter to one's back, holding a short blade in one's mouth, and diving into the turbulent water required not only immense courage and mastery of swimming but also a complete disregard for life and death. Only a Long Hu lineage member could undertake such a mission. At this moment, Gu Cai’s exceptional underwater skills were the group's last hope.