Reassured by Lu Yu, the county magistrate recalled the sensation when he ate the Huangsong cake.
"At that time, my tongue did feel a slight numbness, and there was a hint of bitterness. However, I hadn't eaten this type of cake before and assumed the baker had accidentally added too much seasoning."
"If that's the case, the poison you ingested is definitely not oleander. Oleander juice is merely bitter and does not cause numbness on the tongue," Lu Yu paused. "Asarum has a pungent and bitter taste, and it also causes a numbing sensation on the tongue."
As Lu Yu spoke, he produced two pieces of Huangsong cake and placed them on the table before the magistrate.
"Please observe these two cakes. One is a normal cake, and the other contains Asarum. Oleander is indeed difficult to find, and I cannot locate it within a short period. However, you can examine these two samples first."
Lu Yu picked up the cakes and broke them open before the magistrate's eyes, allowing him to smell the contents.
"If a small dosage is used, the aroma will not change significantly. Therefore, I have added a large amount of Asarum to the other one. Please smell them and see if the aroma matches what you tasted that day."
The magistrate leaned closer to the cakes, comparing the scents. The aroma of the second cake indeed closely resembled the scent from the cake he had tasted previously.
"Even if it's Asarum poisoning, how can you be sure it wasn't the town mayor's doing?" The magistrate put down the cake and looked at Lu Yu again.
Seeing the magistrate's words, Lu Yu knew he had gained his trust.
"There are three reasons. Firstly, I believe Town Mayor Zheng wouldn't be foolish enough to harm you while in the same room."
"Secondly, Town Mayor Zheng had no opportunity to handle this plate of cakes today. If it were merely done by a subordinate, it would be too risky, as no one wishes to leave leverage in others' hands."
"Thirdly, if Manager Zheng and I were conspiring, I would have been waiting outside when you were poisoned. Upon hearing you had fainted, I could have entered to either claim credit or harm you."
Lu Yu did not state it explicitly but used the third point to remind the magistrate.
The magistrate also recalled that when he woke up, those around him had told him that his fainting was thanks to Deputy Town Mayor Chen and Doctor Zhao, and that he was fortunate that Deputy Town Mayor Chen happened to encounter Doctor Zhao and brought her to treat him at the time of his poisoning.
Seeing the magistrate lost in thought, Lu Yu was completely relieved. It seemed the magistrate had been persuaded. He raised both arms and bowed respectfully to the magistrate.
"Your Excellency, please grant me permission to thoroughly investigate this matter."
"Very well, I grant it. However, there must be a deadline. I give you three days to find the culprit."
"Your Excellency, I would prefer to investigate privately to avoid alerting the suspect."
The magistrate nodded and turned to call out, "A Qian!"
"Your subordinate is here!" A shadow flashed, and before Lu Yu could react, she was already standing before the magistrate.
"For these three days, you will follow Lu Yu and assist her in the investigation. While within the manor, you are to stay by her side at all times to ensure her safety. Fulfill any needs she may have to the best of your ability."
This wasn't protection; it was supervision. He feared she and Zheng Yu might collude to deceive him. What a cunning old fox, worthy of being a magistrate. Compared to Zheng Yu, she was far inferior.
The two left the room. Lu Yu's first action was to ask A Qian for a set of servant's clothes. Disguised as a servant, it would be convenient to move around the manor.
Lu Yu first used her past makeup skills to draw wrinkles all over her face. Then, she put on the clothes, appearing as an old woman nearing fifty.
A Qian acted as a guide, taking Lu Yu to the kitchen to become one of the servants delivering meals and dishes daily. No one else would be suspicious.
As it was nearing noon, Lu Yu eagerly volunteered to deliver food to Zheng Yu, citing her desire to help with the workload since she had been accompanying the magistrate.
After some polite refusals, seeing Lu Yu's genuine willingness to help, they no longer declined. With thanks, they happily went off to rest.
Hearing the knock on the door, Zheng Yu assumed it was the usual servant delivering food and did not get up. He shouted towards the door, "Leave the food outside the door, and I'll get it later."
"Knock, knock, knock." The knocking continued. Zheng Yu got up reluctantly, suddenly realizing it might be Lu Yu. He quickly went to the door and yanked it open.
"Come in, come in quickly!" Zheng Yu opened the door, scanned the area outside, grabbed Lu Yu's arm, and pulled her inside.
"It really is you." Zheng Yu examined Lu Yu's disguise from head to toe. "Your face, tsk tsk tsk, it's so realistic."
"By the way, does Yi'er know about my situation?"
"Yes, he guessed it last night."
"Then now he..." Zheng Yu was somewhat worried.
"When I saw Young Master Gu, he showed no expression, likely suppressing his emotions. With Xuan'er accompanying him, you shouldn't worry too much. If you leave quickly now, he can get better."
Zheng Yu nodded, pulled Lu Yu to sit down, and they exchanged the information they had gathered. To avoid arousing suspicion from Zhao Ran and Chen Qi, Lu Yu did not stay long in Zheng Yu's room before leaving with the food containers.
In the afternoon, as Zheng Yu had mentioned, Lu Yu paid special attention to A Yi, who cooked, and A Er, who delivered the food. Both were specifically responsible for Chen Qi's meals, and A Er delivered food to Chen Qi every day.
According to Zheng Yu, Wuji saw A Er go to Zhao Ran's room yesterday and stay there for a long time before coming out. When she emerged, she appeared flustered and was startled when she encountered other servants on the way, which was very suspicious.
That evening, as A Er was about to deliver food, Lu Yu stopped her. "A Er, you seem quite busy today. How about I deliver this dish for you?"
"N-no need." A Er seemed startled, withdrew her arm, clutched the food container to her chest, and hurried away.
Lu Yu watched her retreating back, deep in thought. After a while, Lu Yu, under the guise of needing to relieve herself, secretly slipped towards Zhao Ran's courtyard. Along the way, she did not see A Er returning.
With a creak, A Er pushed open the door and emerged from Zhao Ran's courtyard. Acting like a thief, she scanned her surroundings, then quickly lowered her head and hurried away.
From a distance, Lu Yu peeked out from behind a large tree and quickly followed.
She saw that A Er did not return along the original path but instead went to a corner within the wall, squatted down, and began digging the soil with her hands. After ensuring no one was around, she quickly took out a package from her chest and buried it there before hurrying away with her head lowered.
Once A Er had completely left, Lu Yu walked to where she had buried the item, kicked it twice, and retrieved the cloth bundle.
A Er, due to excessive nervousness, fell into a ditch on her way back.
When she hobbled back to the kitchen, Lu Yu had already returned.
Lu Yu, upon her return, noticed A Er had not yet arrived and thought she might have missed something. She went to other places, only to find out A Er had fallen into a ditch. It seemed even heaven was helping her.
Behind the yamen, there was a ditch specifically for waste disposal. A Er had likely fallen into it.