Based on Jiang Li's understanding of Qin Ji, it is not easy to catch him in the act.

So from the very beginning, she never thought that she could arrest the person directly during the day.

What she wanted was something related to the corpse oil refined by Qin Ji.

In this way, she could find a way to extract the composition of the corpse poison and make an antidote.

Unexpectedly, Bai Zhou actually brought back the barrel of oil used to burn Qin Ji's corpse. It was as if God was helping her.

Seeing Princess Jingling's face full of satisfaction, Bai Zhou finally breathed a sigh of relief.

"Then Princess, next..."

Jiang Li took out a piece of paper from his sleeve and said, "Next, I'll have to trouble Master Bai to take people to check this place."

Bai Zhou took it and opened it. There were five big words written on it: Sanhe Garment Shop.

"A clothing store? What does this have to do with this case?"

Bai Zhou looked puzzled.

Jiang Li smiled and said that this matter was thanks to the Ninth Princess.

Yesterday at the herbal medicine shop, Jiang Li asked her to think carefully about whether there was anything that An Wanqiu and Yin Jia did at the same time in the past few days but she did not do.

Gu Yuyan started counting from the first three days when the two fell ill, from the time they met in the morning to the time they parted in the evening.

After saying it once, Jiang Li didn't feel anything was wrong.

Until Miaomiao came over and said, "Princess, the dress you ordered is ready. Do you want to see it now?"

Gu Yuyan had no mood to look at clothes, so she waved her hand and asked Miaomiao to go down.

Jiang Li casually asked, what custom-made clothes?

Gu Yuyan then said, "A new clothing store has opened in the capital. They say they spent a lot of money to hire an embroiderer from Jiangnan. Both the fabric material and the workmanship are unique. They just opened a while ago. Because they specialize in high-end customization, the first batch of customization is currently only open to daughters of officials. Business is very tight."

"It's a pity that you, Aunt Huang, were not in the capital a few days ago. I don't know your sizes, so I only customized two sets for Sister Yin Jia and Sister Wan Qiu."

Jiang Li remembered what Xiao Zhu said before, that Yin Jia liked the clothes Xiao Jiu gave her very much, and she thought it must be this set.

"Have both of theirs been delivered?"

Gu Yuyan nodded. "My set was said to be more complicated to make, so it was delivered a few days late. Theirs was delivered two days earlier, and Sister Wanqiu wore it just two days ago. It looked so beautiful."

Jiang Li's mind flickered, and he glanced at Xiao Jiu, "Show me your set."

When Miaomiao brought the clothes, Jiang Li looked at them carefully twice.

In terms of style, it is actually not much different from the clothes in other ready-made clothing stores in Beijing.

But in terms of embroidery, it is indeed good.

"Aunt Huang, do you like it? I'll have someone customize a set for you, okay?"

Seeing Jiang Li studying it again and again, Gu Yuyan couldn't help but ask.

"Xiaojiu, can you give me this set?"

"ah?"

Gu Yuyan was stunned.

"I seem to know why your sister Wanqiu and sister Yinjia were poisoned." Jiang Li put the clothes under his nose and smelled them.

Although the clothes were fumigated with spices, there was a faint scent of incense lingering on them.

But Jiang Li's nose has always been different from that of ordinary people.

There is a strange smell hidden in it that most people cannot detect.

Gu Yuyan was stunned when she saw this and pointed at the dress, "Aunt Huang, what do you mean?"

Jiang Li nodded.

The reason why this newly opened clothing store opened the first batch to daughters from official families was not a marketing tactic to create a shortage of products, but because it takes time to refine corpse oil.

Moreover, if a young lady from an official family had health problems, she would only go to the imperial physician. Ordinary people would not know about it at all, let alone think that it was related to a clothing store.

By the time the capital was in complete chaos, it had become like a plague.

The clothing store will not be involved in any scandal.

Jiang Li narrowed her eyes. What Qin Ji came up with was indeed a good idea.

On the night when Bai Zhou led his team to stake out the Qin Mansion, Jiang Li took Gu Yuyan's clothes and sent people to the An Mansion and Yin Mansion to get the custom-made clothes for the two respectively.

After Jiang Li soaked the three sets of clothes with special potions, he put the soaking water into the space's detection system for inspection.

Sure enough, they all contained highly poisonous substances.

Now Jiang Li understood why An Wanqiu was the most seriously ill, while Yin Jia's illness was less serious.

According to their maids, An Wanqiu wore the custom-made clothes to the herbal medicine shop the next day after she got them, while Yin Jia only tried them on for a while before taking them off because she had to inspect the farm afterwards, intending to wear them again in two days.

Because this set of clothes is fully custom-made, even the inner fabric is soaked in corpse oil. Once put on, the corpse poison contained in it will penetrate into the body through the skin.

In addition, the weather has started to get warmer these days, and this fabric is thicker than ordinary fabrics.

If you wear it and sweat, the corpse poison inside will seep in faster.

Later, Jiang Li sent someone to take the medical records from the Imperial Hospital to various major mansions for inquiries overnight. The result was just as she expected: all the young ladies from official families who had been in trouble had ordered clothes from Sanhe Garment Shop.

Bai Zhou was shocked after hearing what Jiang Li said.

"This...this is simply...unheard of!"

He has been an official for many years and has seen many major cases, but this is the first time he has seen someone so vicious.

"Master Bai, this Sanhe Clothing Store is a newly opened clothing store. If I'm not mistaken, it must be related to the Qin Mansion. When you are investigating..."

"Don't worry, Princess. I know what to do."

Bai Zhou was very angry because he failed to catch the criminal yesterday. Now that he was going to investigate this Sanhe Garment Store, he would definitely dig it up inside out!

On the other side, the Qin Mansion.

Everyone was called to the yard. Qin Ji sat at the top, looking at the people below with cold eyes.

"In the past few days, has anyone seen anyone in the mansion leave their room in the middle of the night?"

Qin Ji spoke slowly, staring at the trembling servant.

Everyone was stunned when they heard this and looked at each other.

Then Qin Ji said, "Apart from the few servants who patrol the mansion at night, think carefully, have you ever seen anyone leave their room in the middle of the night?"

Seeing that no one responded, Qin Ji sneered and said, "Think about it carefully. If anyone can provide useful information, there will be a generous reward."

"Master...Master, I had a stomachache in the middle of the night and saw Zhang San in the yard."

A maid slowly raised her hand.

Zhang San, who was called out by name, fell to his knees and said, "Master, please be kind. I'm just delivering something to the old man and will be back to my room after that."

Qin Ji glanced at him, and immediately two people appeared and dragged Zhang San away.

"Master... I saw it too, I saw it..."

Outside the yard.

A figure quietly watched everything that happened inside.

The woman clenched her handkerchief, eavesdropped for a while, and then quietly left.