As the beginning of winter approached, the weather became increasingly cold. Yuan Xi walked out of Yun Niang's room and took a deep breath. The cold air immediately penetrated into her heart and lungs, causing her to cough uncontrollably.

She gathered her clothes and walked slowly on the stone road. The dark blue sky was pressing down heavily. All she could see were dead branches and withered flowers. She didn't know when this huge mansion had become so dead and cold. It was as if there was a deep well that would eat people hidden in the darkness, silently swallowing up all the freshness.

She suddenly felt a chill all over her body, this chill came from the bottom of her heart, like a winding vine, entangled her bit by bit, almost making her unable to breathe. At this time, someone came behind her and put a cloak on her. The familiar breath penetrated into her nose, and a pair of steady and dry hands tightly embraced her, making the sadness and fear dissipate in an instant.

Yuan Xi turned around in surprise and said, "You're back."

Xiao Du was wearing a moon-white straight tie, and the tenderness hidden in his eyes was enough to melt all the ice. He rested his chin on her forehead and smiled, "Do you miss me?"

Yuan Xi was never used to such intimacy in public, so she quickly dodged his warm breath on her face and said, "We just separated this morning, what's there to think about?"

Xiao Du pursed his lips and said faintly, "But I feel like it's been a long time."

Yuan Xi blushed, then put on a serious face and said, "Stop joking, let's be serious. Did you find anything when you went to the charity house today?"

Xiao Du's eyes sparkled, but he did not answer and asked, "What about you? Is Yunniang willing to tell you?"

Yuan Xi sighed and told him everything about what happened when she saw Yun Niang today. Xiao Du held her hand tightly and said excitedly, "You mean, she entered the house after Aunt Cai died, but why did she have to admit all the charges? Why didn't she want to explain to me?"

Yuan Xi shook her head and said, "If Aunt Cai's death had nothing to do with her, then she must have been instructed by someone to go to the room to get the calligraphy. But I still can't figure it out. If Aunt Cai was already dead before Yunniang entered the room, then who killed her and how did they do it?"

Xiao Du's face showed a hint of deep thought, and he continued, "I went to see Aunt Cai's body again today, and indeed I found something unusual. Fortunately, I asked the charity house to preserve her body with ice, so they didn't dispose of it carelessly."

Yuan Xi knew from his expression that he must have an important clue, and asked quickly, "What is it?"

Xiao Du said, "I found that her nails were dyed yellow, but they were not before. I suspect that she may have had some kind of juice on her hands before she died, and the low temperature caused by the ice cubes during this period of time caused the juice to change color. So I was thinking of asking you, you have read many medical books and adventure travel notes, is there any common plant in those books that is highly poisonous and can leave marks on people's hands, and will not show yellow until it is frozen."

Yuan Xi frowned and pondered for a while. Some vague ideas came to her mind, but she couldn't figure it out clearly, so she said, "There aren't too many poisonous plants. If you can see them often at home, there will be even fewer. I'll go back and check, and I should be able to find it soon. But why are you sure it's this plant? Is it related to Aunt Cai's death?"

Xiao Du nodded and said, "The coroner has not yet figured out what kind of poison caused Aunt Cai to die. Her symptoms do not seem to be caused by common poisons such as arsenic. Moreover, as long as someone in the mansion has bought these poisons, there will definitely be clues. So I suspect that the murderer may have used a poisonous herb that can be found in the mansion. When I was on the march, I knew that the roots of many plants are highly poisonous. Maybe we have such a deadly thing in our mansion for the murderer to use."

Yuan Xi also thought that this guess was reasonable, and nodded, "Okay! Wait for me for a day, and I will definitely help you find it out!" After that, he turned around and hurriedly went back.

Xiao Du grabbed her and said softly, "I'll go with you."

The two of them went into the room together, picked up many books about herbal medicine, and looked through them one by one. They even asked the servants to bring dinner to the room. Finally, Yuan Xi held up a book, pointed to a page, and said excitedly, "Look at this!"

Xiao Du took it and read it carefully. He saw that there was a plant called "Dripping Guanyin". If planted properly, it would drip water from the tip or edge of the leaves. Because it looked like Guanyin, it was very popular among wealthy families. However, according to the book, the rhizome of this plant is highly poisonous. If the juice is accidentally taken, it will cause black skin and swollen lips and cheeks. It will be fatal in less than a moment. The juice will turn yellow in extremely cold environments.

Xiao Du's face was filled with excitement. He pounded his fist on the book and said, "It must be this. The way Concubine Cai died was very similar to the description of the poison. I will ask the gardener in the mansion if he has ever grown this plant."

As expected, according to the gardener in the mansion, there were many bonsais named "Dripping Guanyin" planted in the mansion, and there was one outside Aunt Cai's room. Xiao Du then asked someone to bring the maid Gui He to ask about it. Gui He had been locked up for a few days and was already dizzy. When she saw Xiao Du, she burst into tears and said, "My Lord, I really didn't do anything. Please let me go!"

Xiao Du's face turned pale, and he said, "Answer my questions properly. As for whether it is an injustice or not, I know it in my heart."

Gui He lifted her sleeves and wiped her tears, then said timidly, "What else does Lord Hou want to ask? As long as Gui He knows something, she will not dare to hide it."

Xiao Du took out the book and pointed at the picture of "Dripping Water Guanyin" and asked: "Take a good look and see if you have any bonsai plants like this in your yard."

Gui He hurried forward and took a closer look. Suddenly he exclaimed, "That's it! It turns out it's called the Dripping Guanyin!"

Xiao Du sensed something strange in her words and asked hurriedly, "Do you know it? Where did you see it?"

Gui He recalled: "On the day Aunt Cai died, she said she was in a bad mood and asked us to go to the yard and bring in two bonsais to make the house more refreshing. At that time, she specifically mentioned that there was a plant in our yard that dripped water from the edges of its leaves, which looked very interesting, and asked me to find it and bring it in for her! It was this Dripping Guanyin."

Xiao Du's hand holding the page of the book suddenly tightened, and he almost shouted, "You said she specifically asked you to bring this Weeping Goddess of Mercy in. Was it after she disguised herself as you and went out and came back, or before?"

Gui He was startled by his words and replied tremblingly: "It was after she came back, and then two hours later, she died..."

"During this time, has anyone else entered the room?"

"no!"

Xiao Du fell back heavily on the chair and thought about the whole thing from beginning to end. Finally, he rubbed his brows as if he was very tired and said, "I understand. You can go out first."

Gui He was taken out of the house by two guards. Xiao Du sat alone facing the flickering candlelight for a long time, until a candle flower burst out from the wick, and then he seemed to wake up. He slowly stood up, opened the door, and walked back into the room in the dark night.

"What! You said Aunt Cai really committed suicide!" Yuan Xi stood up in shock and accidentally dropped the books stacked beside him to the ground.

Xiao Du bent down and picked up the books one by one. His voice was a little muffled as he said, "That's right. She asked Gui He to bring in a pot of Weeping Goddess of Mercy and took the juice from one of the stems. At that time, some of it got on her nails by accident. Then she swallowed the highly poisonous juice and died soon after. She deliberately had someone move in the pot of Weeping Goddess of Mercy. No one entered her house during this period, and Yun Niang never touched the juice, so it naturally had nothing to do with her."

Yuan Xi was becoming more and more confused, frowning and asking, "But why did she do this? Why did she deliberately hang herself in this way, and then leave a suicide note saying that it was Nanny Yu who did it?"

Xiao Du finally picked up all the books, turned his head and looked at her, with some self-mockery in his eyes, he said: "I think, except Aunt Cai herself and Yun Niang, no one else would know."

Aunt Cai is already dead, but Yunniang is still alive, although she is not much different from a dead person now.

After she finished listening to Xiao Du's story with a blank look in her eyes, she just curled her lips slightly and said, "So what? How does the Marquis want to deal with me now?"

Xiao Du looked at her silently for a long time, and said with a hint of sadness in his voice, "Yun Niang, until now, are you really unwilling to tell Du'er even a single word of the truth?"

Yunniang's once plump cheeks had long since dried up, and her eyes were like deep pools of stagnant water, no longer able to stir up any waves. She rubbed her legs, which had become somewhat stiff from sitting, and said, "I have been pretending to be crazy for these years, and the Marquis has also taken care of me for these years. Our relationship as master and servant should also come to an end. If the Marquis thinks I am guilty, he can send me to the government and let me die on my own. If he thinks my crime is not punishable by death, Yunniang would like to shamelessly ask to go to the Shuiyue Temple outside the city. From now on, I am willing to fast and chant Buddha's name every day, always with a green lamp by my side, to atone for my life's sins, and also to pray for the Marquis and his wife to have a safe and smooth future, and to have more blessings and a long life."

Xiao Du closed his eyes tightly, then suddenly stood up, picked up a wooden comb beside him, and said, "When I was little, Yunniang combed my hair and dressed me every day. I have no way to repay you, so today I will comb Yunniang's hair for the last time."

After saying this, he ignored Yunniang's surprised look, untied her loose bun, and held the dry messy hair in his hands, and combed it for her clumsily. The black and white hair slid through the teeth of the comb, and he seemed to see the many years of companionship slipping away in his palms.

He couldn't help but let out a bitter smile, his throat choking with sobs, and said, "When I was little, I often suspected that maybe you were my mother, otherwise why would you be so good to me. When I was ten years old, I secretly heard my father's retainer say that he would redeem you and swear to marry you as his legal wife and treat you well. But you said you had no interest in him and would rather stay and take care of the young master. But I know that after he left, you secretly cried in the room all night. At that time, I swore that when I grow up, I must respect you as I respect my own mother." He sighed heavily, and his hand holding the wooden comb trembled a little, and said, "No matter what happens, Yunniang will always be my Yunniang. I'm just sorry that Du'er can't take care of you anymore in the future. Take care."

At this moment, Yunniang's shoulders were shaking like leaves in the wind. Xiao Du tied up her crooked bun, put down the wooden comb in his hand, strode out of the door, and never looked back. Yunniang covered her mouth tightly and made a low sob. In the distance, Xiao Du's majestic voice came, "Send her to Shuiyue Temple, take good care of the nun in the temple, and don't embarrass her."

The wooden comb fell to the ground at some point, entangled with the prematurely grown gray hair, as if those years could never be returned.

##

The sunset glowed slowly across the sky. Nanny Yu arranged for today's dinner and was walking towards her room alone. Suddenly, a figure rushed out from the path beside her and rushed towards her.

Nanny Yu was startled, and before she could dodge, the man had already slapped her hard on the face. Nanny Yu was dazzled by the slap, and when she finally saw who it was, she couldn't help but ask in shock, "Third Miss... Third Miss, what happened?"

Xiao Zhixuan's eyes were red as she glared at her and said, "It's you, right? I know it's you! It's you who killed my aunt!"

Nanny Yu was panicked and covered her face, saying, "I don't understand what Third Miss said at all."

Xiao Zhixuan's body was shaking with anger. She held onto a tree trunk and said, "You went to look for mother some time ago, and I happened to be sleeping in her room. At that time, I just thought that the voice sounded familiar, but I didn't think much about it. Yesterday, I heard my eldest sister-in-law talking about the letter left by my aunt, and then I remembered that the person must be you, right!"

Nanny Yu put down her hand that was covering her face, a trace of cruelty flashed in her eyes, but she quickly regained her composure and said, "Miss San has no basis, you can't talk nonsense. The Marquis has said that Concubine Cai clearly committed suicide, how can you blame others. If Miss San wants to vent her anger, you can beat or scold me, but this crime cannot be arbitrarily charged."

"You!" Xiao Zhixuan was so angry that she was shaking, but she also knew that she had no basis for her accusation, and the princess was standing behind Nanny Yu, so she couldn't do anything to her. At this moment, she heard Nanny Yu whisper, "I would like to advise Miss San to not be so willful in the future. Aunt Cai committed suicide because of you..."

Xiao Zhixuan raised her head suddenly, her eyes full of disbelief, while Nanny Yu had already straightened her hair that had been messed up by her, turned around and slowly walked away.

(End of this volume)