Ren Zu froze in the suffocating blackness of the Cavern of Eternal Night.
"Say your names?"
The request echoed in his mind, more terrifying than any roar of a beast. The language of the world contained ten thousand characters and millions of combinations. There were names for every star in the sky, every drop of water in the ocean, and every emotion in the human heart. To guess two specific names in this absolute darkness, without a single clue, was harder than finding a specific needle in the depths of the Eastern Sea.
Panic clawed at his throat. Ren Zu quickly turned his consciousness inward, whispering frantically to the glowing speck in his chest.
"Hope Gu! You guided me to this mountain. You told me the secret of their existence. Surely, you must know their names? Tell me!"
Hope Gu flickered weakly, its voice trembling with apology.
"I do not know," it replied. "I am Hope. I can guide you to the destination, and I can give you the courage to knock on the door, but I do not hold the key. I only know where they are; I do not know who they are."
Ren Zu felt his heart sink into the abyss. He had no choice. He was a blind man standing on the edge of a cliff, and he had to leap.
He began to guess.
"Are you Light?" he shouted, his voice cracking against the stone walls.
"No." The answer was immediate and cold.
"Are you Darkness?"
"No."
"Are you Greatness?"
"No."
Ren Zu shouted name after name, dragging words from the depths of his memory.
"Power? Glory? Destiny? Fortune?"
"No. No. No. No."
The denials were monotonous and unfeeling.
He guessed for days that bled into nights, though in the Cavern of Eternal Night, time was a meaningless loop.
He became thirsty, his tongue swelling in his mouth like a dry sponge.
He became hungry, his stomach twisting into painful knots.
His voice grew hoarse, turning from a shout to a rasp, and finally to a broken whisper.
Eventually, silence reclaimed the cave.
Ren Zu collapsed. He lay on his back, his limbs spread out on the freezing stone. He was dying.
His breath was weak, fluttering like a candle flame in a gust of wind. His heartbeat was slow and irregular. His consciousness began to fade, drifting away like smoke into the void.
"Human," the rigid voice spoke from the darkness, sounding almost pitying. "You are almost dead. Your persistence is admirable, but your body is dust. We will let you go. We will not trap your corpse here. Use your remaining time to crawl out and take one last look at the world before you return to the earth."
Ren Zu's fingers twitched. The temptation to give up was sweet, like warm honey. To simply close his eyes and sleep...
But his hand moved. Slowly, painfully, he clenched his fist over his chest.
"No..." Ren Zu rasped, the sound barely audible. "Even if I die... even if I rot in this darkness... I will not give up Hope!"
Inside his chest, Hope Gu heard this declaration. It felt the unyielding spirit of its host. It was deeply touched.
"Human!" Hope Gu cried out.
Suddenly, it erupted.
It did not flicker. It did not glow. It exploded with a blinding, transcendent radiance.
However, Ren Zu was too old. His body was too broken, and the Cavern of Eternal Night was too vast. The light of Hope could not pierce the infinite darkness of the cave; it could not illuminate the walls or reveal the hidden forms of the Gu worms.
It could only illuminate one thing: Ren Zu himself.
In that sea of blackness, Ren Zu's chest became a beacon of white light. He looked down at himself.
He saw his withered hands. He saw his bruised knees. He saw the path of blood he had dragged behind him.
And in that light, seeing his own broken form, Ren Zu felt a sudden, thunderous surge of clarity.
He realized that he was not infinite. He was defined.
He had a shape. He had limits.
Why did he fall when he tripped? Because of gravity.
Why did he bleed when he struck stone? Because flesh is softer than rock.
Why was he dying? Because life has a beginning and an end.
To catch a Gu, one must understand the nature of the world. The world was not a chaotic mess of random events. It was a structure. It was built on boundaries. It was built on standards.
To climb a mountain, one must follow the path. To exist, one must follow the laws.
Ren Zu's eyes widened in the light of his own Hope. He looked into the darkness, not seeing the Gu, but understanding what they must be.
With his final breath, forcing the air through his ruined throat, Ren Zu whispered a single word:
"Regulation."
For a heartbeat, there was no sound. The darkness of the Cavern of Eternal Night seemed to recoil, as if the word itself was a torch that burned the shadows.
Then, a long, deep sigh echoed from the void. It was not a sigh of exhaustion, nor of defeat. It was the sigh of a locked door finally finding its key. It was the sound of recognition.
"Human..." the rigid voice spoke again, but this time, the hardness in its tone had softened into solemn respect. "I admire your perseverance. To find order in chaos, and to find the name in the silence... you have guessed correctly. I am indeed Regulation Gu."
From the absolute darkness, a strange phenomenon occurred. A portion of the blackness condensed. It did not glow with light, but rather, it solidified into a shape so distinct that Ren Zu could sense it without seeing it.
A Gu worm flew out of the void. It moved in perfect straight lines—up, over, down. It did not flutter or meander. It landed precisely in the center of Ren Zu's bloodstained palm.
Ren Zu brought it closer to the light of the Hope Gu in his chest.
He saw it clearly now. It was a Gu worm that looked like it was carved from black iron. It was perfectly Square. Its body had no curves, no softness, and no deviation. It was sharp, edged, and rigid. It was the physical manifestation of boundaries, limits, and standards.
"Since you have spoken my true name, I am bound by the laws of the Great Dao to obey your commands," Regulation Gu stated, its voice vibrating against Ren Zu's skin like a tuning fork. "I can help you set limits. I can help you build walls. I can define what is right and what is wrong."
Ren Zu's fingers curled around the cold, hard body of the Gu. A faint smile touched his lips. He had succeeded. He had found the power to capture Time.
"Then..." Ren Zu wheezed, his vision blurring as death crept closer. "Help me... catch... Lifespan Gu."
However, Regulation Gu did not move. It remained inert in his palm.
"I cannot do that alone," Regulation Gu said calmly. "I am only half of the law."
Ren Zu's eyes widened in horror. "Half?"
"Look at me, Human," Regulation Gu said. "I am Square. I am rigid. I can create a cage, but I cannot create the door. I can set the boundary, but I cannot traverse the path. I am the standard, but I lack the method. Without my brother—the Round one—the system is incomplete."
The voice in the darkness continued, explaining the cruel reality.
"I am the Square that does not change; he is the Round that adapts. I am the wall; he is the wheel. Without the Round, the Square cannot roll. Without him, Regulation is just a stone that cannot move. To catch the elusive Lifespan Gu, you need a net that is both firm like a wall (Me) and flexible like a web (Him). You need both."
"Who... is he?" Ren Zu gasped, clutching the square Gu. "What is his name?"
Regulation Gu fell silent.
From deeper in the darkness, the second voice—the sharp, cutting voice from before—laughed softly.
"You guessed the Square, Human. But can you guess the Round? I am right here. I am the method. I am the adaptation. But unless you call my true name, I will remain formless."
Ren Zu lay paralyzed on the floor. He held the hard, cold Regulation Gu in his hand, but his heart was sinking.
He had spent his Youth for Strength.
He had spent his Prime for Wisdom.
He had spent his final breath for Regulation.
And it was not enough.
He had found the Regulation, but he still needed the Other. He needed to name the concept that complemented Regulation—the thing that was Round, flexible, and governed how things moved.
And he had no time left to guess another name. The darkness of the cave began to press in on him, heavier than before, ready to claim the first human as part of the earth.