Shi Ting took the flashlight and searched the tunnel walls at each of the eight exits, but found only some blurred, indistinct marks.

Yan Qing’s heart sank when she saw those marks. “It looks like there really were hints here once, but they’ve been erased. These marks must have been scraped away with a sharp implement.”

Shi Ting nodded. “Whoever erased these diagrams did not dare remove the marks entirely, because they also needed the diagrams to find the correct exit in a place where all sense of direction is lost.”

“But the remaining marks have no discernible shape—they’re far too abstract. Only the person who erased them could make sense of them.”

The two examined each of the eight tunnel openings in turn. Without exception, every original marker had been obliterated. The remaining traces bore no resemblance to the original forms and yielded no clues about the diagrams’ content.

Shi Ting took Yan Qing’s hand and they sat down on the bed. After all that effort, both of them felt utterly exhausted.

Who could have imagined they had found the entrance only to find themselves unable to locate the exit—and to be trapped inside this secret passage to boot.

To conserve the battery, Shi Ting switched off the flashlight, and with it went the light. Only the kerosene lamp remained, casting a dim, murky glow.

“Are you afraid?” Shi Ting reached out and drew Yan Qing into his arms.

Yan Qing shook her head. “We’ve weathered so many storms together. I believe this time will be the same—we’ll come through safely.”

Shi Ting smiled and gently ruffled her hair. “Yan Qing, if we truly become trapped here and have no way out—if all we can do is wait for the end—would you tell me your secret?”

Yan Qing’s body gave a slight shudder, though she quickly composed herself.

She had long suspected it. A man as perceptive as Shi Ting would surely have noticed her strangeness long ago. She had arrived in Xin Guo more than a hundred years before her own time, carrying the thoughts and knowledge of the twenty-first century. No matter how well she disguised herself, she would seem out of place before a sharp-eyed person.

He had always known, yet he had never asked, never spoken of it.

“Very well.” Yan Qing could not help but tighten her arms around his waist. “If we truly cannot get out, I’ll tell you a story.”

“Suddenly I’m rather looking forward to it.” Shi Ting’s laughter drifted down from above her head.

Yan Qing laughed too. “I’m a little hungry. I wonder if the occupant here has any food.”

“Those two boxes—we haven’t looked through them yet.”

“Let’s open them.” Yan Qing got up and walked to the boxes. They were unlocked; a gentle lift of the lid opened them.

But the contents of the boxes disappointed them. Besides some clothing and daily necessities, there was no water or food whatsoever.

“It seems your guess was about seven or eight parts right.” Yan Qing said. “Judging by what’s in the boxes, the occupant is likely a woman. The shoe size matches the footprint you found behind the waterfall. And there are music scores.”

There were about a dozen music scores. When she turned to the last one, Yan Qing recognized a familiar piece—the very composition “Love Unrequited.”

Unlike the others, this one was handwritten. Besides “Love Unrequited,” there were several other compositions, though none of them had been passed down.

“I believe this is Huiyuan’s manuscript.” Yan Qing could not read music scores, yet she could tell the person who wrote it possessed deep skill. The notation was written with almost no hesitation, as if completed in a single breath.

Shi Ting examined it in the faint lamplight and confirmed Yan Qing’s inference. “So the one who has been hiding in Baiyun Nunnery and killing people really is Huiyuan.”

“But why would Huiyuan want to kill Huian and Huixiu? From what Jing Xin and the others said, the three of them were as close as sisters.”

“Do you remember that magnificent main hall?”

“Could it be connected to the hall’s construction?”

Shi Ting recalled, “I was still abroad at that time and did not know much about affairs back home. But I later heard from Mother that the First Madam had donated a large sum of incense money to a certain nunnery. The Old Madam was also involved in that matter.”

Once Shi Ting put it that way, Yan Qing understood the entire sequence of events.

“The First Madam felt threatened by Huiyuan. She feared the General would truly bring Huiyuan back home. Given the depth of the General’s feelings for Huiyuan, once he brought her back, he would never let her suffer the slightest grievance—it was even possible the position of principal wife would be given over to her. The First Madam was terrified of this happening and wanted to eliminate Huiyuan quietly, without anyone knowing. But eliminating Huiyuan would inevitably alert the General, who would investigate the matter to the very end. The only solution was to make Huiyuan die by her own hand.”

Shi Ting adjusted the lamp wick. “But Huiyuan lived in seclusion and refused to see even the General. The only way to make her die of her own accord was to have an insider do the deed. So the First Madam approached Huian and offered to fund the construction of a new hall for Baiyun Nunnery in exchange for her killing Huiyuan. Huixiu was also part of the scheme.”

“Given Huian’s obsessive devotion to Baiyun Nunnery, she was truly capable of doing something like that.” Yan Qing thought of the two old sachets. “They kept the sachets at their sides not out of longing, but out of guilt.”

“But where has Huiyuan been for the past decade or more, and why did she choose to return and seek revenge at this particular time?”

“Only she herself knows that.” Yan Qing sighed. “If we’re lucky, she may not discover that someone has intruded. If we’re unlucky and she finds us, we’ll be trapped in here—and the mystery will never be solved.”

“Yan Qing, stay here and don’t move. I’ll go take another look at those tunnel openings.”

When Shi Ting returned, he picked up a twig from the side and sketched on the earthen floor the remnant diagrams from the walls of all eight openings.

It was like piecing together a puzzle: assembled together, the full picture could be seen, but taking any single piece at random made it impossible to identify the original form.

Shi Ting held the kerosene lamp and moved it back and forth over the ground, hoping to find some clue within.

By the time the kerosene in the lamp burned out, he had found nothing.

Without the kerosene lamp’s light, the passage was instantly plunged into darkness, the silence so absolute one could hear a pin drop.

“Rest for a while.” Shi Ting said gently. “Sleep for a bit.”

“I can’t sleep.” Yan Qing sat at the head of the bed and tried to make out his face in the darkness. “I’m thinking about Huiyuan—how has she endured living in a place like this, without a single ray of light? How has she survived it?”

Then she suddenly raised her voice. “Shi Ting, do you think she might have already left? Huixiu and Huian are both dead. Her great vengeance has been fulfilled—she should have no reason to stay here.”

“I don’t think so.” Shi Ting said. “She has lived here for many years and has a deep attachment to this place. Most importantly, her piano is still in Baiyun Nunnery. She would not abandon her piano. This underground passage runs in all directions; she comes and goes as she pleases. She has ample time to enjoy the sunlight and rain above ground, even to move through the various courtyards of Baiyun Nunnery.”

“I understand now. On rainy nights, she goes to play the piano. For one thing, the night she was harmed was a rainy night; for another, she can use the sound of the rain as cover to ease her longing for music. Someone as devoted to the piano as she is cannot be separated from it.”

“So she will not leave.”

Yan Qing spoke, and her stomach chose that moment to growl in protest. From morning until now, they had eaten only breakfast.

Shi Ting took out his pocket watch and lit the flashlight to check it, only to be surprised: the watch’s hands were still frozen at the moment they had entered.

“There are even magnetic fields interfering down here.” Shi Ting frowned. “Whoever built this place embedded a large quantity of magnets, specifically to disrupt a compass.”

“The person who built it was truly ingenious.”

In a place without light, where the passage of time itself seemed to have stopped, with no exit and no hope, everything felt as though it had frozen in place.

Fortunately, both of them possessed exceptional mental fortitude, and even in this situation they remained calm.

Time passed—how much, no one could tell. The surroundings remained utterly silent, not a sound to be heard.

Yan Qing lay down on the bed and slept for a while. When she woke, she saw Shi Ting crouching on the floor with the flashlight, studying those sketched diagrams.

She was hungry and thirsty, but there was nothing to eat or drink here, so she could only endure.

Shi Ting was learned and well-read, with a mind like a steel trap. If even he could not decipher these diagrams, no one else stood a chance.

“Are you hungry?” At some point Shi Ting had come to sit beside her, taking her hand in his.

“One kiss and I’m not hungry anymore.” Yan Qing smiled and pecked him on the cheek. “Spiritual nourishment is nourishment too.”

Shi Ting drew her into his arms, his voice carrying a faint suppressed guilt. “I’m sorry, Yan Qing. I promised to protect you properly and never let you come to any harm, yet once again I’ve let you fall into danger.”

“As long as I’m with you, I’m not afraid of life or death. If you say sorry again, that’s when I’ll truly be angry.”

Shi Ting managed a faint smile. “I’ve imagined many ways to die. Starvation was never one of them.”

At the mention of starvation, Yan Qing suddenly recalled a case she had once handled, and recounted it with animated interest: “I once heard a story about a man and a woman who went mountain hiking together. They tumbled off the mountain and the woman was lightly injured while the man broke his leg. They were stranded at the foot of a cliff with nothing to eat. Before rescuers could arrive, they had no choice but to go hungry. Many days passed, and at last rescue teams came. They brought the woman to safety, but the man was nowhere to be found.”

Shi Ting raised an eyebrow. “It can’t be as simple as missing, I imagine.”

“The rescuers searched the cliff base for a long time but found no trace of the man. According to the woman, she woke one morning and he was gone. But the man’s leg was broken—he could not walk on his own. So everyone concluded he had been dragged away by a wild animal.”

Yan Qing’s eyes glimmered. “Where do you think the man went?”