Under the dusty building, there is really something else. However, to Qin Shiwai's surprise, he originally thought that these underground buildings must be the kind of eerie, torch-lit like a ghost domain, just like the scene when he was locked up in Zhao Prison in Shangjing City, but the fact is that the light below is very abundant.

At this time, the sun was shining outside the small building, but there was also plenty of sunlight in the space deep underground, which made him stunned. Looking up at the aisle where he was, he found that at the top, there were copper mirrors inlaid with each other, and those rays of light were actually reflected by these copper mirrors by some unbelievable means.

"What kind of means is this?" He asked, pointing to the top of his head.

"Your Majesty, this is Xu Lai's ability!" Shu Chang said happily: "He was born in a hundred engineering departments in the secret door, these are what he made with the news of the agency, and I don't know the specific principle. He hadn't been here for a long time, but these things were just a piece of cake for him, and when we were in that remote village, many experiments were done underground, and it was he who set up these mechanisms to keep us from seeing the light of day. Ha, if it weren't for these means, how could he have coaxed my junior sister into his hands?"

"What a talent!" Qin Feng was convinced in his heart, but he was contemptuous of Shu Chang's words, what did Xu Lai coax your junior sister to? Look at that Xu Lai's demeanor, maybe it was your tall junior sister who used some means to deceive that Xu Lai, right?" Why didn't you see him today?"

"Oh, he's found something good." Shu Chang said: "The last time Ning Zeyuan came back, didn't he bring back red wine, glass utensils, and some mirrors?" Xu said that the reflection effect of these mirrors is much better than that of copper mirrors, and if all the copper mirrors here are replaced with this kind of glass mirror, the environment will be better. He's swept away all these things from my house, and he's sitting at home studying this thing! He hadn't seen anything before."

"Estimating the time, Ning Zeyuan should be back soon. It's been almost half a year, and not long ago a merchant ship has brought back news of them, and things have been almost done, and when they come back, maybe they will be able to bring back a craftsman who can make this kind of glass."

"That couldn't be better." Shu Chang said happily: "This glass is a good thing. If you bring it in from overseas, there will be a limited quantity, and it's not easy to transport, it's very fragile, so if you can make it yourself, that's good."

The group walked along the long alleyway, and the houses on either side were basically empty, and they were full of messy things.

"Are there many people coming over this time?" Qin Feng asked. From Shu Chang's mouth, he knew that the 100 engineering departments in the secret door specialized in all kinds of organs, and the means were quite good, in Shu Chang's eyes, the current Ministry of Works' skillful hands were in Xu Lai's eyes, but he was just an apprentice-level figure. If Xu Lai is a professional background, then the skillful hand is a pure wild way. But what skillful hands have brought to Da Ming Qin Feng naturally knows in his heart, and now that there are craftsmen with these skills, Qin Feng naturally wants to give full play to their greatest ability.

"There aren't many people from the 100 engineering department." Shu Chang said: "The people of their subject are in high demand in the rivers and lakes, and it is really easy to get a lot of money, so ah, there are few people who are really willing to settle down to study the department, they are very harsh in recruiting people, how many people learn a bottle and a half of water and leave, and there are very few people like Xu Lai. But it doesn't matter, with him alone, he can stand up to a hundred or ten other hundred engineering guys, and he also brought several disciples over."

"You know that there is an ordnance research institute in the Ministry of Industry, where do you think it would be good for Xu Lai to work?" Qin Feng asked.

"Since he is here, it is naturally all arranged by His Majesty." Shu Chang nodded, "There, it's indeed the right place for him."

As they spoke, the two of them were already standing in front of a spacious room, the same as outside, there was plenty of light here, but what was terrifying was that there were several skeletons here, real skeletons. More than a dozen people in white robes were surrounding one of them, discussing something lively.

"You still have these bone racks with you?" Qin Feng said in surprise.

"I brought only a few representative ones." Shu Chang said helplessly: "In my hometown, there are really a lot of such bone frames, oh, that white-bearded old man, although he is not a personal disciple of the family teacher, but he is above the orthopedics, but among them, the holy hands, these bone frames, are made by him himself. His craft, that's amazing."

Seeing that the old man was holding a thin piece of iron in his hand and gesturing something on the bone, Qin Feng turned his puzzled gaze to Shu Chang again.

"He used this piece of iron to connect the broken bones of the person, so that the injured could recover faster. Back then, he really killed a lot of people in order to get this. Later, I figured out that after the iron pieces he used were inlaid with them, it didn't take long for them to rust, and the people who died were because of those rusts, and later Xu Lai solved these problems for him. However, Xu Lai has to make those steel sheets that are not rusty too laborious, so ah, his research has not progressed quickly. Now that he has arrived in Daming, he has what he wants, and Daming's steelmaking skills can solve his biggest problems, and he can create various types of steel pieces according to his needs, Your Majesty, you look at his strength."

The dozen or so guys in the room who were discussing enthusiastically noticed the group of people standing at the door, the white-bearded old man bowed slightly to Qin Feng and his party, and then turned around and went to talk about his own, basically ignoring them.

"These people have a lot of weird tempers." Shu Chang said to Qin Feng with some embarrassment.

"People who have the ability will not have a good temper." Qin Feng smiled, "Just like you."

"What's wrong with me!" Shu Chang said unconvinced." Let's go, Your Majesty, there is a place for my junior sister's experiment ahead."

Qin Feng came over today, in addition to taking a look at the medical school, the most important thing is to verify the experiment of exchanging blood that Shu Wan is doing, if it is really feasible, it will be an epoch-making change for the army under his command, and even for the people of the whole world.

An officer in a black uniform walked over, this is a captain of the Eagle's Nest.

"Your Majesty, everything is ready." Captain Dao.

In the spacious room, more than a dozen people in prison uniforms were blindfolded and tied to chairs, and these people were today's experiments. In front of them was a wooden workbench where Shu Wan was busy.

"These people are death row inmates. The lowly was ordered to secretly bring them out of the Eagle's Nest prison and brought them here." The lieutenant whispered.

Qin Feng nodded and walked straight in.

In front of Shu Wan, there was a whole set of shiny utensils, and at this moment she carefully put a shiny needle on top of a thin tube, and the other end of the thin tube was connected to a small translucent leather bag.

And on the table, more than a dozen such things have been prepared.

"These needles are hollow, and it is up to him to draw blood and exchange blood." Shu Chang explained: "Including those thin pipes, they are all made by Xu Lai, there are only a dozen sets here, but it took Xu Lai a lot of time, if this experiment is finally verified to be reliable, the most difficult thing is how to mass produce these things. It's easy to make a beautiful weapon, but it's much harder to make such a hollow steel needle. By the way, there are also these thin pipes, all of which are made of duck intestines, Your Majesty, don't underestimate this thing, I heard Xu say, to make a suitable and usable one, it takes more than ten processes in the middle and the scrap rate is extremely high."

"As long as the experiment can be successful, I can find a way to solve other things, as long as Xu Laiken teaches others the techniques of making these things."

Shu Chang nodded, with the current manpower and material resources of the Ming Dynasty, even if it is a sea of people tactics, these problems can be solved.

Shu Wan and a few of her assistants walked up to the death row inmates with these gadgets, skillfully inserted the steel needles into the arms of those people, and in the restless writhing of the prisoners, the bright red blood flowed down the hollow steel needles into the leather bag.

It didn't take long for the small bag to be filled with bright red blood, Qin Feng looked at those prisoners, it didn't seem to be a big deal, for a person like him who came out of the battlefield, losing this bit of blood was really nothing.

Each bag was numbered, and then the blood in the bag was exported little by little and packed in a small white dish with the same number, Shu Wan took out a bottle, used an ear scoop the size of an ear scoop, scooped out a trace of medicinal powder from the inside, and poured it into the blood.

Qin Feng walked over comfortably, staring at the blood in the small saucer.

After a few moments, there were some subtle changes in the blood. Shu Wan nodded with satisfaction, and an apprentice on the side marked a blood bag with the word C.

The same process was repeated, and soon, more than a dozen blood bags were marked with A, B, C, D.

Shu Wan breathed a sigh of relief and turned his head to look at Qin Feng: "Your Majesty, next, I will interchange the blood of the same reaction into the human body, and the D number can be injected into anyone else's body at will."

"Let's get started!" Qin Feng nodded.

The leather bags were hung high above the prisoners' heads, and the steel needles were inserted into the veins above their arms again, and the blood flowed silently down the leather tubes, the steel needles, into the bodies of those people.

"Your Majesty, the rest of the time is to wait." Shu Chang said." As long as they can still be alive, it proves that this thing can be successful."

"How long does it take to see the problem?"

"One day at most, the damned ones will die." Shu Wan said." As long as you don't die, then you have succeeded."

Qin Feng turned his head to look at the captain of the Eagle's Nest, "Bring these people back to the Eagle's Nest and detain them in solitary confinement, eat and drink well, rest well, and report their physical condition directly to Commander Guo every day. This matter is top secret."

"Yes!" The captain's face was a little pale, and he had just watched the whole process directly.