Mo Bai arrived at the display area in the East District. One entire wall was a glass display case, and inside, various items that resembled eyeballs, skulls, hearts, hands, feet, and the like were scattered about. They were all submerged in containers, with price tags ranging from 0.2R to 2R underneath them.

A well-dressed employee in a suit stood beside the display case. Mo Bai approached him and asked, “The things in the display case all look pretty good. Why isn’t anyone buying them?”

The employee was the auction registrar. He explained, “These are items that some customers have replaced. They’re still usable, but they have one problem or another, so we can only sell them cheaply. If you can accept their defects, the price is negotiable.”

“Those eyeballs are beautiful. What’s wrong with them?” Mo Bai asked.

The registrar said, “Whoever they look at turns to stone. The original owner suffered greatly because of them and eventually came to our auction house to have the eyeballs replaced.”

“Medusa!” Du Heng muttered.

Mo Bai asked, “The original owner sounds pretty powerful. Were they a native of the town?”

“According to regulations, we cannot disclose any information about the person who supplied the organ.” The registrar smiled courteously.

“Then how can we get around that restriction?” Mo Bai asked.

The registrar indicated 'according to regulations' rather than giving an outright refusal, which meant there was still room for negotiation.

“If you wish to purchase this item, we are obligated to provide you with information about it.”

“I’m actually quite interested. Even if I don’t replace my own eyeballs with them, they’d still be a nice collectible,” Mo Bai said.

She suspected that the pair of eyeballs might turn into a card.

The registrar said, “Then I’ll have to give you a detailed introduction. The original owner of this item came from Sunset City. That’s a famous metropolis, which is nothing like our small town. It’s extremely developed and the customers there are also very wealthy. They often bring us items that never resist at all, so our trading house is very fond of customers from Sunset City.”

Sunset? Wasn’t that the same as dusk? The card Li Ming used to resist Requiem of Confession was the Dusk Walker, which contained the contamination of another Ultra-Star monster.

The trading market was really a fascinating place.

Mo Bai asked, “Why don’t the items from Sunset City resist?”

“Who knows?” the registrar said. “Those items are all rather strange. They keep saying things like, ‘Everything has a dusk,’ ‘Everything will come to an end,’ ‘I merely reached the finish line ahead of schedule,’ and so on.”

People contaminated by the power of Dusk will lose the will to live?

Mo Bai said, “Then forget it. I do like turning people to stone, but these eyeballs came from Sunset City. What if I replace my own eyes with them and start shouting things about ‘the end’ and ‘the finish line’ like those other items? If my brain got messed up along with them, that would be terrible. I don’t want to buy them.”

The registrar didn’t get angry. He merely smiled at Mo Bai.

Mo Bai continued examining the display case. Suddenly, she spotted a painting with a price tag of 2R beneath it.

The painting depicted a teacher giving a lesson. He was a medium-built man wearing casual clothes, and his back turned to the viewer as he wrote on a blackboard.

On the blackboard were the words, “The expression for the two-focus curve function is not (x-a)+(y-b)=r. The correct expression for the two-focus curve function is…” The rest was blank, as though he were in the middle of writing.

The moment Mo Bai saw the painting, her pupils contracted. Fortunately, she was wearing a helmet, otherwise, it would have been difficult to keep her expression under control.

She gripped the hem of her clothes tightly.

Du Heng didn’t know what was going on. He was still pointing at the painting and commented, “What is the person writing? It's giving me a headache. What a terrifying language.”

Worried that someone might be able to hear them through their helmets, Mo Bai did not answer Du Heng.

The two-focus curve function that the teacher wrote was actually what they called an S-shaped function, whose graph was an S-shaped curve. Meanwhile, (x-a)+(y-b)=r was the expression for a circular function, whose graph was a circle.

Extracting the key terms from the teacher’s sentence and plotting them on a function graph formed a giant capital-letter “SOS.” The teacher in the painting was using mathematics to send out a distress signal!

There was only one person who would do something like this: Ye Pingjun, who cleared the most insane mathematics instance.

Three months before Disease Town, Ye Pingjun mentioned that if any of them ever got into trouble, they should write down the expressions for the two-focus curve and the circular function. That way, the others would know that their teammate was calling for help when they saw them.

He even forced them to memorize all sorts of mathematical expressions. Ding Xun and Sheng Yan, who were both hot-tempered, were driven to lie down on the floor and throw tantrums, insisting that they simply couldn’t do math.

Liu Congyi and Gu Tiandong had better tempers, but they also politely refused.

Liu Congyi directly said, “I think writing the three letters ‘SOS’ would be faster. How long would it take to write this whole string of symbols?”

Ye Pingjun replied, “If you write ‘SOS,’ the enemy might discover it and erase it. Mathematical formulas look more like clues, so the enemy might be inclined to leave them alone. It’s not troublesome. Once you memorize them, writing them will be quick.”

Gu Tiandong asked, “Then why don’t we agree on a pattern that’s easy to remember and convenient to use as a code?”

Everyone unanimously agreed with Gu Tiandong’s idea, and Ye Pingjun’s teaching plan went up in smoke.

Only Mo Bai memorized all the formulas he taught them after seeing them once. Her high school math was quite good, after all. She was merely refreshing her memory.

But remembering them was useless. If no one else could remember or understand them, then writing them down was like lighting a lamp for the blind, a complete waste of effort.

She just never expected that Ye Pingjun’s formulas would come in handy here.

Mo Bai kept her emotions under control and asked with the same curious tone she used when asking about the eyeballs, “Why is a painting so expensive?”

“This is more than just a painting. There’s an entire person inside, and the person’s total value is 2R. If his brain were auctioned separately, that brain alone would be worth 1R. It’s a high-value item,” the registrar said.

Mo Bai asked, “Why is he inside the painting? If I buy it, can he come out?”

The registrar gave an awkward smile. “He is a dangerous customer who injured many of our employees. Eventually, the customer who supplied him used a method to seal him inside this painting and sold him to the trading house at a discounted price of 1R. If you buy the painting, you’ll probably have to figure out how to get the person out yourself. We can try to contact the previous customer for you, but you’ll have to pay a service fee, and that customer may charge you as well.”

Mo Bai said, “You are ripping me off! You only spent 1R to acquire him, yet you’re selling him for 2R. And now I still have to pay a service fee just to use him! Can’t you lower the price?”

“If you’re truly sincere about buying, 1.5R would be acceptable,” the registrar said, quite agreeably.

Mo Bai asked, “How much is your service fee for locating a customer?”

“1R,” the registrar said.

“That’s too expensive!” Mo Bai said. “Give me your bottom price.”

“How about this? We can sell it to you at the original price of 1R, but you have to guarantee that after you subdue him, you’ll sell his skin to us.”

Mo Bai didn’t even have 1R, but she remained calm. “You’re really short on skin, huh? What’s the market rate for intact skin?”

“The purchase price for ordinary skin is 0.5R, and it can fetch 2–4R at auction. Flawless skin is purchased for 1R and starts at 5R at auction. Flawless, healthy, supple, youthful, and beautiful skin is purchased for 1.5R and can fetch as much as 10R at auction,” the registrar said.

“10R?” Mo Bai gave a cold laugh. “Your customers are really rich!”

The registrar smiled. “Some of our major clients provide our trading house with a steady supply of merchandise.”

What kind of major clients? The doctors who operated on Yang Lingxi at the Abandoned Hospital? Or one of the people with real power in this town? Or perhaps…

A possibility suddenly occurred to Mo Bai. She lowered her voice and said to the registrar, “I used to be a researcher at Biological Research Institute No. 7.”

The registrar immediately became respectful and lowered his voice as well. “I never imagined that any researchers from the institute survived. Your institute was a steady source of merchandise for our trading house, but now that it has fallen, our supply is extremely tight. Do you have any stock on hand?”

Sure enough, Biological Research Institute No. 7 conducted human experiments all along. Some of the failed test subjects were still alive but weren't used as food for the underground monster, so Professor Yang sent them to the trading house controlled by Gao Siyun.

Under the control of that malicious energy, the dragon slayers ultimately became evil dragons themselves.

Mo Bai pointed at Du Heng. “This is all the stock I have left. What grade would you say his skin is?”

The registrar took out a device resembling a thermometer gun and scanned Du Heng’s hand. “Flawless skin. 1R.”

Mo Bai raised her hand. “What about mine?”

The registrar scanned it as well, then said, “The highest-grade skin. Good heavens, the condition of your skin is incredible. Our trading house can make an exception and buy it for 2R. But esteemed customer, there’s something I should warn you about. Flawless skin has to be harvested from a living subject without anesthesia. Anesthetic injections leave needle marks on the skin and also reduce its elasticity, turning it into defective merchandise. So we always harvest skin from living subjects, and it will be very painful.”

“Then how do you make sure the merchandise doesn’t struggle? Wouldn’t struggling cause damage too?” Mo Bai asked.

The registrar immediately gave Mo Bai a suspicious look.

Mo Bai realized her mistake at once. Thinking of the researcher identity she fabricated, she guessed at a possibility and boldly said, “Now that I think about it, our research institute once had a by-product called Manipulation Thread. It can control a person’s body without leaving any marks.”

“You really are a senior researcher! Manipulation Thread has been a huge help to us,” the registrar said ingratiatingly. “You really don’t have any stock left?”

Mo Bai more or less understood the whole process now.

Dai Qianzhong secretly sold Ye Pingjun and the other two to the trading house, and the trading house attempted to use Manipulation Thread to restrain and harvest their organs.

However, Ding Xun, Ye Pingjun, and Gu Tiandong all went through Count’s Castle. Not only did they see Manipulation Thread, they even used it themselves.

The trading house certainly acted covertly, but Ding Xun possessed both Extrasensory and Synthesia. There was no way Manipulation Thread could escape her notice.

It was even possible that when Dai Qianzhong negotiated about selling them, Ding Xun already sensed something was wrong through Synthesia.

The merchandise couldn’t hear the conversations between customers and the auction house, but Ding Xun could use Synthesia to tap into a customer’s or employee’s sense of hearing. She might have heard everything long ago.

They probably didn’t expect that Dai Qianzhong would be so powerful. Ding Xun might even have launched a surprise attack, only to discover that Dai Qianzhong could control gravity. And so the three of them were subdued just like that.

Ye Pingjun was turned into a painting and sold, so the painting was probably the effect of a card. As for the other two, Mo Bai had no idea where they were.

An idea suddenly struck Mo Bai. She lowered her voice and said, “I do have some merchandise.”

“Then…” The registrar’s expression became suggestive.

“But this is the only batch I have left, and I’m counting on selling it for a high price so I can replace all my organs. If I replace my organs, I won’t have any money left to buy this painting. How about this? I’ll sell you the merchandise, but you give me the painting for free.”

The registrar looked troubled. “If you let me see the merchandise, I’d definitely give it to you. It’s only a painting, after all. But I haven’t even seen the merchandise. How can I sell it to you?”

“You’re really stupid,” Mo Bai said. “I’m still standing right here. I’m already your trading house’s customer. I can’t run away. Besides, my skin is one of the items I'll sell. You’ve already seen the merchandise, haven’t you?”

“This… well…” The registrar appeared to have the authority to give things away, but he hesitated, worried that Mo Bai was tricking him.

“Do you have any binding contracts? I’ll sign one with you. If I can’t provide you with the merchandise, I’ll give you a body covered in flawless skin in return. The deadline… three days. How about it?”

In the next three days, either Mo Bai would destroy this instance, causing the trading house to vanish and the contract to automatically become invalid, or Mo Bai would bring Dai Qianzhong, Pang Mian, or Xie Xingchen to the trading house, for them to be skinned alive!

“Deal!” The registrar quickly scribbled out a contract, then took out a blood-red inkpad box.

“You just need to press your fingerprint here, and it’ll be binding.”

“Excellent.”

Mo Bai took the inkpad box. With a sweep of her arm, she moved her beautiful hand gracefully through the air. The registrar’s eyes involuntarily followed it.

“Done,” Mo Bai said.

The registrar came to his senses and looked at the inkpad box and the contract. Sure enough, there was a red thumbprint on the contract, and the inkpad box also bore the mark of a pressed fingerprint.

Although he didn’t see the customer actually press her fingerprint, there shouldn’t be any problem.

So the registrar said, “The contract is valid. I’ll get the painting for you right away.” He turned around and opened the display case. Du Heng whispered, “Where did that finger come from?”

The registrar didn’t see it, but Du Heng watched Mo Bai take a severed thumb out of her pocket and secretly press it onto the contract.

Mo Bai said, “When the townspeople attacked us earlier, I cut off quite a few hands. I didn’t notice that a few fingers got caught on me, so I brought them along.”

Du Heng gave her a thumbs-up.

Just then, the registrar took down the painting and handed it to Mo Bai.

Mo Bai accepted the painting.

Finally, she rescued Ye Pingjun!