"Solar Worm"’s nozzle, conduit, and fuel tank are integrated into a single unit, appearing as a twenty-centimeter-long insulated metal tube, the width of an arm guard, which can be strapped to the arm or calf. At first glance, the shape is somewhat like a beetle, with the "chelicerae" being rows of leather and metal buckles for securing it.

He wore the Solar Worm on the inside of his left forearm, looking a bit bulky, but his sixty-nine points of Strength allowed him to ignore the weight.

"The Solar Worm is best suited as a mecha module, which can be integrated into my self-designed light mecha." Han Xiao was still hung up on his idea of a light mecha. He already had a plan; since he chartered Farian’s transport plane, he could build the light mecha while running errands in the novice village.

At this moment, a yellow-skinned man with graying hair walked over, staring at the Ghost Gauss Sniper Rifle Han Xiao had placed aside, and exclaimed in surprise, "I’m not mistaken, this is an electromagnetic kinetic energy weapon!" He then turned to look at Han Xiao and asked, "Are you selling this gun? I'm willing to offer five hundred thousand… no, one million!"

Han Xiao sized him up, already having an idea, and feigned ignorance, asking, "Who are you?"

"I'm the chief mechanical technology consultant invited by Lu Cheng, Lei Zhenyu. You seem to be a mechanic as well, so you should have heard of me."

Han Xiao didn't react.

"You wouldn't have never even heard of my name, would you? Are you a self-taught mechanic? How rare." Lei Zhenyu said in surprise, shaking his head, and directly asked, "I want this electromagnetic kinetic energy firearm. Name your price."

"Do I look like I'm short on money?" Han Xiao pointed to the expensive material parts on the lathe.

Lei Zhenyu's eyes suddenly lit up. "You're a self-taught mechanic. I can guide you in technology in exchange for your gun. You definitely need a master like me to guide you. Only by listening to your seniors can you avoid going down the wrong path. I can tell that you actually yearn to learn from a master. I'm here, opening my arms to you. This is a once-in-a-lifetime opportunity. You'll regret missing it for the rest of your life."

He didn't know that the electromagnetic kinetic energy sniper rifle was made by Han Xiao. In his impression, self-taught mechanics were all technically unskilled, so he wanted to exchange teaching Han Xiao for the gun. He was, after all, a mechanical master, and he wouldn't even teach ordinary people. Giving Han Xiao such a valuable opportunity, as long as the other party knew the goods, he felt that exchanging the electromagnetic kinetic energy sniper rifle was more than enough.

Han Xiao's eyes twitched. This was the first time he'd heard such a shameless self-praise, almost on par with his own.

In fact, Han Xiao knew Lei Zhenyu's background. This guy was very famous in the mechanic world of Aquamarine Star. He was a very high-level mechanic, a master without a doubt. He was from the same era as Old Man Lu, active decades ago, and had long since retired. Like Old Man Lu, he had no masterly demeanor at all, both being quite flamboyant.

Han Xiao knew why Lei Zhenyu was in Black Pine. Speaking of which, it was related to Old Man Lu's four blueprints mission. Lei Zhenyu happened to be a link in this cumbersome hidden mission.

Back then, Lu Cheng abandoned his daughter, who was only a few years old, leaving her to Old Man Lu to raise. He himself entered the wilderness to become a warlord. Because of this, Old Man Lu had a big fight with him, unable to understand Lu Cheng's choice. The father-son relationship was very strained, almost to the point of no contact.

Lu Cheng gradually became a powerful warlord in the Southern Continent, facing all kinds of dangers.

On the surface, Old Man Lu didn't want to have any contact with his son, but in fact, he was secretly paying attention to Lu Cheng. He asked his old friend Lei Zhenyu to come to Black Pine to help Lu Cheng, protecting him secretly. Lu Cheng was completely unaware of this, and was very pleasantly surprised that he could invite a master to be stationed at the armory.

The opportunity for the four blueprints to begin was when Lei Zhenyu had to leave Black Pine for some reason. Only then did Old Man Lu provide Lu Cheng with help in another way. He didn't want to meet Lu Cheng awkwardly, so he left the blueprints and left West Capital, his whereabouts unknown.

"Perhaps that's what a father is." Han Xiao sighed. Why was Zhu Ziqing's "The Back View" a classic? Because those who had experienced it could resonate with it. Even an old rascal like Old Man Lu had concerns.

Suppressing his emotions, Han Xiao composed himself and said, "I can trade with you. I want advanced knowledge."

According to his memory, Lei Zhenyu understood advanced knowledge, but players couldn't learn it from him. He wanted to give it a try.

Lei Zhenyu said earnestly, "Young man, don't be too ambitious. You're a self-taught mechanic. Your level isn't enough to understand advanced knowledge. I'll teach you something else."

"No, I only want advanced knowledge."

Lei Zhenyu declined, saying, "But you won't understand it."

"That's even better. You don't have to worry about me learning it. I'll just look at it for an hour. Just treat it as me being curious, okay?"

Lei Zhenyu was immediately speechless. Advanced knowledge was very precious, belonging to secrets and trump cards, not easily taught. Controlling the source of knowledge was very important. Although he was very curious about the structure of the electromagnetic kinetic energy firearm, it wasn't valuable enough to exchange for advanced knowledge. Even if Han Xiao said he didn't understand it, he didn't want to take any risks.

Lei Zhenyu hesitated for a while, unwilling to give up. "I can't teach you advanced knowledge, but I can exchange it for a machine made with advanced knowledge."

As expected, it wouldn't be so easy to get advanced knowledge. Han Xiao had been mentally prepared, and wasn't discouraged. Instead, he thought about Lei Zhenyu's suggestion. If he used something he could make to exchange for a new machine of the same level, it didn't seem like a loss.

However, the Ghost Gauss Sniper Rifle he carried with him was a repeatedly enhanced version, and he still needed to use it. He planned to make a new one to exchange with Lei Zhenyu.

Han Xiao nodded in agreement with this suggestion and said, "I'll make a new one for you."

"You made the gun?!" Lei Zhenyu was shocked. He saw that Han Xiao was a fresh face, and a self-taught mechanic, so he thought the gun was made by someone else. He didn't expect to be mistaken.

All six nations were secretly developing electromagnetic kinetic energy weapons, and hadn't yet passed the experimental stage. Just being able to make a barely stable electromagnetic kinetic energy weapon meant that Han Xiao was a mechanic of the same level as him. Lei Zhenyu thought of his previous self-proclaimed masterly attitude, and even his old face felt a little ashamed.

To actually act high and mighty in front of a mechanic of the same level was too embarrassing.

Fortunately, Lei Zhenyu had thick skin, and quickly put away the contempt in his heart, adopting a proper attitude, and regarding Han Xiao as an equal.

At this moment, a guard hurried over and quickly whispered a reminder that Han Xiao was also a legendary assassin.

Lei Zhenyu was shocked. He sized up Han Xiao. There were many mechanics who could do research, but those who could fight were as rare as phoenix feathers and dragon scales. His level of importance attached to Han Xiao rose another level.

Having strength meant being valued wherever you went.

"Please come with me. I'll show you my storage room." Lei Zhenyu coughed dryly, hurriedly changing the subject to resolve the awkwardness, and there was a hint of respect in his words.

The two came to the restricted area inside the armory. This was the living quarters of senior researchers. Lei Zhenyu's room was a spacious suite, with all kinds of living items, as well as a wine cabinet and a bookshelf, all made of high-grade maroon wood by hand, expensive. There was also a simple small lathe in the corner of the room, indicating that the treatment was very good.

Lei Zhenyu opened the wine cabinet and activated the hidden door switch. The wine cabinet slid open, revealing a secret storage room. He beckoned Han Xiao to enter. Inside, there were glass display cabinets placed against the wall, all containing mechanical equipment. Lei Zhenyu went directly to the innermost display cabinet.

"I have four pieces of equipment made with advanced knowledge. Let me introduce them to you." Lei Zhenyu pointed to the glass display cabinet, and began to prattle on.

The advanced knowledge Lei Zhenyu mastered was biased toward micro-modification. These four advanced machines were all related to nanotechnology.

"Nurse I-type" Biological Particles, appearing as a tube of thick black colloid, were actually decomposed special nanoparticles. They could be injected into the body, and quickly get rid of negative states when injured, poisoned, or bleeding, clear toxins, and rapidly coagulate blood. This was a consumable for medical use.

U9 Colloidal Bulletproof Film, appearing like transparent glass, would briefly become colloidal when subjected to impact, canceling kinetic energy, and then instantly solidify, clamping the object. For example, if a bullet was shot at it, it would be clamped in an instant, as if the bullet head had always grown inside, like transparent colorless amber. It had high defensive properties, and the colloidal state was not easily damaged, making it suitable for making bulletproof vests.

Fermillo Condensate, appearing as a pile of shaving cream-like foam, was used to inject into the interior of the machine to cool it down and reduce the cooling time of the machine. Then it would rapidly degrade, not clogging the operation of the internal components of the machine. Taking the Solar Worm as an example, the cooling time of overheating was 20 seconds. Using Fermillo Condensate, the cooling time could be reduced to three to five seconds, with significant effects. This was also a consumable.

PE-0 Nanofiber, appearing similar to biological tendons, was jet black throughout, with a smooth surface and full of toughness. It was a nanomaterial, and twisting or stretching would generate elasticity far beyond its volume.

Han Xiao could only exchange for one of them.