My girlfriend is a Miao demon.

Inside the Circle Art City, warm yellow light shines through retro glass lampshades, casting dappled shadows on the ground, creating an eerie atmosphere that sends chills down one's spine.

Suppressing his anxiety, Xiang Nanfeng walked to the center of the living room and paced back and forth. He finally spotted the exquisitely crafted, solid wood-framed fireplace against the east wall. He walked over and reached for the fireplace switch.

With a soft hum, the electric heater slowly blew out warm air, and orange-red simulated flames danced inside the furnace. The flickering light and shadow actually created a sense of being there, as if chatting by the fire. The warmth enveloped the chill around you, but it couldn't dispel the gloom that lingered in your heart.

Mao Xigu, holding onto the armrest of the single sofa, sat even more upright:

"Forgive my frankness, but based on my understanding of witchcraft, I am quite certain that your father was afflicted by the Illusionary Heart Gu before his death. And this Illusionary Heart Gu is definitely not the kind of trickery I saw or heard about in the Maoxi Miao Village in my early years. This kind of witchcraft must be the most authentic witchcraft, and the person who used it may even have come from ancient times, and may have directly received the skill from Jiang Yang, the ancestor of the Sanmiao."

"Jiang Yang?" Xiang Nanfeng and Zuo Hezi asked almost in unison.

"Is this the Jiang Yang from five thousand years ago that you told me about?"

Xiang Nanfeng was the first to ask a question. Mao Xi Gu Master had mentioned the great war between the Sanmiao five thousand years ago. Miao Yao Pagoda, Miao Yao Zen Temple, and the Lou family all pointed to the era of the dream world as the late Ming and early Qing dynasties, or the second year of the Republic of China when Nanshan Hall was located. However, Mao Xi Gu Master suddenly mentioned the witchcraft personally taught by Jiang Yang. Although Xiang Nanfeng was not sure whether Mao Xi Gu Master's conclusion was correct, the statement about five thousand years ago obviously caught him off guard.

Therefore, Xiang Nanfeng interrupted Mao Xigu Master and asked:

"Wait, didn't you just say that after Panhu betrayed Jiang Yang, he launched a centuries-long massacre against the Hua Miao? Didn't you also say before that after that, almost only the Black Miao remained of the San Miao? How could the Hua Miao witch from five thousand years ago still be able to come to Wangshan to commit atrocities?"

Mao Xi Gu Master unscrewed the mineral water that Zuo Hezi had just handed him. After taking a sip, he gazed at the simulated flames illuminated by the light, his eyes gradually becoming distant. It was as if he had pierced through the barriers of time and space and seen that magnificent ancient era.

"Now I'm going to tell you about Jiang Yang, the ancestor of the Sanmiao, and also the top secret of the Huamiao. It's an ancient legend." Mao Xi Gu Master's eyes lit up as he said to Xiang Nanfeng, "Xiang Nanfeng, you must still remember Associate Professor Wu from the physics department at our school, right?"

"Of course, of course I remember. We met because of him, because of that 'legendary' post you replied to on the forum."

"Yes, the reason I initially believed him, and why I believed you without hesitation when you first woke up, was all because of this legend, because of this top secret."

"Oh?"

Mao Xi, the master of the Gu, had successfully piqued the interest of both of them. Although, he had only slowly said:

"Whether through traditional Eastern mythology, Taoist philosophy, or modern physics, you must know that before the universe was formed, time and space existed in a chaotic state, a state of primordial unity. Regardless of how this state is described, whether in scientific terms or mythological language, in short, the world at that time had no matter; only the will of God existed beyond the chaos—because the will of God can exist without any material carrier. Later, God separated time and space, and the universe was born."

When the word "god" was mentioned, Mao Xigu always chuckled to himself.

"Of course, you know that the God I'm talking about may not actually be a God. I'm just using this way of putting it, and you can interpret it according to your own likes and dislikes."

Then, he paused, and continued, "The world we live in today, every person and every thing, exists clearly within a uniform coordinate system composed of time and space. This is the real world we can perceive and understand. But have you ever considered that between the 'sections' where time and space are separated, there exist 'gaps' that cannot be explained by common sense?"

Xiang Nanfeng and Zuo Hezi held their breath, listening intently, afraid of missing a single detail. Only the soft hum of the fireplace and the voice of Mao Xigu Master remained in the living room.

"Hidden within these 'gaps' is a special secret path, which we call the 'Twin Gates'," said Master Maoxi, enunciating each word clearly. "The two ends of the Twin Gates connect two worlds that exist simultaneously but exist in different coordinate systems. One end is our coordinate system of uniform motion, while the other end is a coordinate system of accelerating motion. This Twin Gate is the secret path to time travel."

"Time travel?" Xiang Nanfeng's heart skipped a beat, a thought buried deep within him for a long time surfacing instantly. Ignoring etiquette, he urgently interrupted Mao Xi Gu Master, "You mean, the world I dreamed of before is behind the Twin Gates? Is Gui Luyao... also on the other side of the Twin Gates?"

When Xiang Nanfeng mentioned the name "Gui Luyao", his voice was filled with an undisguised urgency and tenderness.

Mao west Gu Master looked at Xiang Nanfeng, a hint of understanding in his eyes. He nodded and said, "That's right, the world in your dream must be behind the Twin Gates. Gui Luyao must be there too, and she must have come from there. However, the Twin Gates are not the kind of 'time-travel artifacts' depicted in online novels and time-travel dramas, much less the kind of 'anywhere door' that allows you to travel through time at will. We don't fully understand the rules and principles of this kind of time-space passage, and I don't think anyone else can understand it either."

He stood up, walked to the fireplace, reached out to feel the warmth of the air, and continued to explain:

"The Twin Gates connect two different coordinate systems. For people in our uniform coordinate system, time flows normally on the other side of the Twin Gates; but for people in an accelerating coordinate system, time on our side is relatively still. Have you ever read 'Journey to the West'? Of course, Xiang Nanfeng, I know you definitely have. I'm asking Miss Zuo, have you read 'Journey to the West'?"

"No, I've only heard of it; it's the story of Tang Sanzang and Sun Wukong's journey to the West to obtain Buddhist scriptures." Zuo Hezi shook his head.

"It's alright. But I hope you've heard this saying, often repeated in 'Journey to the West': 'One day in heaven is one year on earth.' Do you know what that means?"

"No, I don't quite understand." Zuo Hezi shook her head again, answering in her stiff but fluent Japanese-accented Chinese.

"Let me explain," Xiang Nanfeng interjected. "The saying 'a day in heaven is a year on earth' is a time system set in ancient Chinese Taoist mythology. 'Heaven' refers to the celestial realm, the abode of immortals. Immortals are long-lived, or rather, immortal. Thousands, tens of thousands, or even hundreds of thousands of years are nothing to them. In this case, a year, such a long unit of time, is very short to them. What an ordinary person on earth experiences in a year is like a day for an immortal in heaven. That's why it's called 'a day in heaven is a year on earth.'"

"Fantasy novels like 'Journey to the West' adopt this kind of time setting from Taoist mythology. For example, a deity like Sun Wukong, when he goes to the Heavenly Court to do something, may only stay in the Heavenly Court for a short while. When he returns to the mortal world, he will find that several months or even longer have passed. This corresponds to this kind of setting."

"That's right." Master Mao Xi nodded and continued, "That's exactly what it means. The two sides of the Twin Gates are two coordinate systems with different movements. One is always moving at a constant speed, and the other is always accelerating. The one moving at a constant speed is slow, equivalent to 'one year on Earth,' and the one accelerating is fast, equivalent to 'one day in Heaven.' Before passing through the Twin Gates, you never know which side is moving at a constant speed, slow, or equivalent to 'one year on Earth,' nor you ever know which side is accelerating, fast, or equivalent to 'one day in Heaven.' But it is precisely because of this situation that time travel through the Twin Gates has great uncertainty and unidirectionality."

"Let me give you an example. The world with a uniform speed is like the Earth, which is also in motion. The frame of reference for this motion might be the sun, moon, and stars. The world with an accelerating speed is like a boat moving along the shore on Earth. If we take the sun, moon, and stars as the frame of reference, then it has both the motion of the Earth superimposed on it and its own motion."

"Time travel through the Twin Gates is like boarding and disembarking a ship. If you are initially in a world of constant speed and the world behind the Twin Gates is accelerating, it's like you board the ship at point A, but when you're ready to disembark, the ship has already reached point B. So even if you return to the world of constant speed through the Twin Gates, you'll be back at point A."

"If you insist on understanding it using the plot of a time-travel drama, it's like you were originally a person from the Tang Dynasty, you traveled there and stayed for a few months, and when you wanted to come back, it had become the Qing Dynasty. On the contrary, if you were initially in an accelerated world, but behind the Twin Gates is a world of constant speed, it's like you got off the ship at point A, but when you wanted to get back on the ship, the ship had already sailed to point B, and you hadn't even reached the Twin Gates."

"So, in other words, you can only cross the Twin Gates once, no matter what? Once you cross it, you can never come back?" Xiang Nanfeng stood up excitedly. "What about Luyao? She came from the dream world, but where is she now? Didn't she go back to the dream world?"

"No, don't rush. What I mean is that you can only use a Twin Gate once, but there's definitely more than one Twin Gate in the universe. It's like a great river, not just one boat." The Master of the Maoxi Gu turned around, his gaze sweeping over the two of them. "Before pushing open any Twin Gate, no one knows what the world behind it looks like, nor can anyone determine which side is a world of uniform motion and which side is a world of accelerated motion. In other words, you never know whether you'll be greeted by the distant past or an unknown future once you step in. Even Jiang Yang himself, who first discovered the secret of the Twin Gates, couldn't fully control all of this."

These words plunged Xiang Nanfeng and Zuo Hezi into deep thought. Both were humanities students, neither possessing the insight of a physicist. To them, the mysteries of space and time were often beautiful because of their enigmatic nature. But in reality, this kind of "time travel" was not an easy and pleasant journey, but rather an adventure filled with the unknown and dangers.

"Back then, Jiang Yang, the ancestor of the Hua Miao, was the first to discover the existence of the Twin Gates. And the legend of the Twin Gates is the greatest secret of the Hua Miao people. Xiang Nanfeng, didn't you want to ask me how the Hua Miao Gu Po from five thousand years ago came to Wangshan to commit evil? Didn't you want to ask me if the Sanmiao were left with only the Black Miao after Panhu's betrayal?" Mao Xi Gu Master's voice rang out again, his voice at least 3 decibels louder than before.

"Is it... the Twin Gates?"

Mao Xigu nodded.

"I think so, I really can't think of any other possibility. At that time, the war between the Sanmiao tribe and Yu Shun was at its most intense. Jiang Yang led the Sanmiao army to take the initiative to move to Sanwei Mountain, intending to use the steep terrain and favorable topography of Sanwei Mountain to offset the numerical advantage of Yu Shun's army and to fight a final battle with them in the mountains, trapping them like turtles in a jar. But no one expected that Panhu, the leader of the Black Miao, would suddenly rise up at this critical moment and betray Jiang Yang."

Panhu opened several passes guarded by the Black Miao, leading Yu Shun's army into the mountains. Jiang Yang's plan completely failed, and she was instead surrounded by the enemy in the Sanwei Mountains, trapped in a desperate situation.

"Jiang Yang knew that the situation was hopeless, and the extinction of the Hua Miao tribe was inevitable in their world. But he was unwilling to let the Hua Miao bloodline and heritage be cut off, nor was he willing to let the tribe's glory completely disappear. So, he selected a group of young and highly talented children in the tribe and taught them all the witchcraft he had learned in his life, as well as the secrets of the Twin Gates."

"Afterwards, Jiang Yang pushed these children into different twin gates, sending them into different parallel universes. In fact, Jiang Yang initially chose Sanwei Mountain as the place for his final battle with Yu Shun because he knew that Sanwei Mountain had the most twin gate passages, so that if he lost the final battle, he could leave a way out for Hua Miao."

Mao Xi Gu Master said, "Therefore, at this time, Jiang Yang hopes that these little Gu witches who enter the parallel universe can be lucky enough to reach the new world of the accelerated coordinate system. In those worlds, they can obtain the power of advanced civilizations, find new twin gates, and return to the old world of the Sanmiao War. With the help of the power of advanced civilizations, they can defeat the Black Miao, take revenge on Panhu, and restore the glory of the Flower Miao tribe."

A brief silence fell over the living room. Xiang Nanfeng was already deeply moved by the legend, lost in silent contemplation. A tribal chief's tragic choice, the uncertain fate of a group of young children. How many of these Flower Miao witches cast into the Twin Gates would actually be delivered to a truly advanced civilization? And even if they did enter a so-called advanced civilization, how would they establish themselves, and would they be able to find a new Twin Gate to return to the old world?

Clearly, Xiang Nanfeng was thinking of only two questions:

Could Luyao be such a young witch doctor? Was I also pushed into the Twin Gate in the same way?

However, compared to Xiang Nanfeng, who had already fallen into the "mysterious events" and repeatedly verified their authenticity, Zuo Hezi was clearly less willing to believe Mao Xi Gu Master's "wild words." She paused for a moment, then asked expressionlessly:

"Hey, I've heard about the history of the Sanmiao's attack on Shun and Panhu's rebellion, but what about the Twin Gates? Since it's top secret, where did you hear that from? You said my father was killed by Jiang Yang's witchcraft, and that five thousand years ago Jiang Yang pushed the witch into the Twin Gates. What evidence do you have?"

"Evidence? You want evidence? Fine, I am the evidence!"

Before Mao Xigu could finish speaking, he flung the open mineral water bottle, which he had only taken a few sips from, into the air. The bottle crashed with a thud against the marble feature wall opposite the living room, splashing water all over the wall and floor.

His sudden action startled the two men. Just as they thought the Master of the Maoxi Gu was angry because he had been questioned, all the water droplets on the floor and walls strangely gathered in one place. Then, with a crackling sound, they shot up the smooth marble wall and rushed straight to the roof, crashing into the plastic-wood ceiling with a thud before finally dripping down like a light rain. The two men were left dumbfounded by this strange rain inside the house!

"Look, the Stubborn Stone Gu."

Mao west Gu Master said calmly.