Xu Tian Cave

　　In front of them was a stone mountain that was completely bare without a single weed growing from it. Not only was this mountain tall, it was extremely large. Even more importantly, there was practically no slope. It was completely vertical.

　　Feng Yu Heng leaned her head back to look. Only when she felt a pain in her neck could she see the peak of the mountain. She could not help but sigh: “Towering in the sky, this must be the type of mountain they are talking about.”

　　Xuan Tian Ming explained to her: “This mountain is named Xu Tian, and it is the tallest mountain in the Ping Xu mountain range, and it is also the most dangerous. The mountain is completely vertical, and its peak is in the clouds. The four sides are completely rocky, so there is no possibility of it being climbed.

　　She curiously asked: “Then what about you? Can you fly over it with qinggong?”

　　Xuan Tian Ming shook his head, “We are not gods. Even if we use qinggong to soar over mountain, we still need many places to leap from. Moreover, although the mountain we soared over was tall, it is not even a third of the height of Xu Tian Mountain. Not even the most amazing expert in qinggong could soar over a mountain with its peak in the clouds.”

　　“So it was like that.” Feng Yu Heng continued to look up, as she began to wonder, “Say, the military camp is not too far from the capital. Normally, such a tall mountain should be visible from the capital. Why have I never noticed it before?”

　　Xuan Tian Ming pointed forward and told her: “The capital is to the North of the mountain. In that direction, there is a large river. The air there is moist all year round, so the water vapor that rises and directly becomes clouds. This also happens to completely hide the mountain.”

　　Feng Yu Heng heard this and felt that it was mystical. Now that she stood at the foot of the mountain, she was quite shocked. However, even more shocking was what followed, as she saw Qian Li pointed at the large rock mountain and tell her: “County princess, Xu Tian Cave is inside this large mountain.”

　　“Hm?” Feng Yu Heng completely froze. Inside the mountain? Could it be… “Is this mountain hollow?”

　　Xuan Tian Ming looked at her idiotic expression and could not help but laugh, gently saying: “If you are really curious, you can pick up the mountain from the foundation and stuff it into your sleeve. That way, you can bring it back to slowly investigate.”

　　She repeatedly shook her head, “No way, no way. My sleeves are not that large. This is a mountain!”

　　While they spoke, Qian Li had already taken a few steps forward. Ahead, there were some soldiers that were standing guard. She looked carefully and noticed that there was something that seemed a little bit different about the mountain; however, she could not tell what exactly was different. She could only push Xuan Tian Ming and follow Qian Li forward.

　　Finally, when the mountain was within reach, the soldiers standing guard saw them come over and kneeled to salute. Xuan Tian Ming told them to stand and quietly ordered: “Open up the mountain.” They then saw tens of soldiers move forward and begin to push the mountain.

　　Feng Yu Heng facepalmed. She had heard the fable of Yu Gong, who had moved mountains.¹ Now, she was witnessing a scene soldiers push a mountain. Thinking about it, she was a little excited!

　　At this time, she heard a “thunk” sound, as a crack appeared in the mountain around where the soldiers were pushing. The soldiers continued, and the crack became wider and wider, eventually forming a large stone door.

　　The door that was opened in the mountain was extremely large. Seeing it personally gave her a pretty large shock. In this sort of era without any mechanical production tools, being able to create such a door in a mountain was not easy.

　　But the truly difficult part still lay ahead. With the door in the mountain being opened up, the soldiers immediately returned to their positions. Qian Li gestured for everyone to enter then entered the mountain with large strides.

　　Xuan Tian Ming pinched Feng Yu Heng’s small hand and said: “Go, let’s go inside. Take a look at the rumored Xu Tian Cave.”

　　She was exceedingly curious as she began to move while pushing the wheelchair. Following behind Qian Li, she entered the mountain.

　　A cold wind blew into her face, causing her to shiver on the spot. She suddenly recalled the natural limestone caves in the South from her previous life. She had once gone to visit one with a tourist group. It was the middle of Summer, but the inside was freezing cold like Winter; however, it was like a beautiful paradise.

　　Looking here, the towering Xu Tian Mountain had a hollow area the size of a seven-story building from the 21st century. In the middle of this hollowed-out mountain, there were many odd constructs. She noticed that there was a spiral staircase along the inside wall of the mountain, and there were soldiers endlessly walking back and forth. There was even a guard tower that was extremely tall. The soldier that stood at the top should have been able to see everything inside this Xu Tian Cave.

　　This was just what she could see in front of her. All around, there were still many paths that led to who knew where.

　　Someone inside came to receive them. After saluting, the said: “16 blacksmiths and their apprentices have already been brought to the forge and are waiting. Will general go there to meet them, or should we bring them here?”

　　Xuan Tian Ming said: “We will go to the forge.”

　　The person nodded then took the initiative to guide them.

　　Feng Yu Heng had never recovered from her initial shock. Xuan Tian Ming had already begun to explain the origin of Xu Tian Cave to her, “This was constructed by the founding emperor of Da Shun. By using 30 percent of Da Shun’s workforce, this mountain was renovated to this degree. Following that, with every ruler following him, they were all more interested in building in this mountain than the building of their own mausoleums. Only with my great-grandfather’s generation could this Xu Tian Cave be considered truly completed and able to be put to use.”

　　Feng Yu Heng could imagine the perseverance of the ancient people when it came to these enormous constructs, but she could not understand. Why exactly did they hollow out a mountain?

　　Xuan Tian Ming knew what she was wondering and said: “In truth, at the time of Da Shun’s founding, this place was made to avoid disasters. At that time, Da Shun’s territories were not as vast as they are now. The battles were long, and there were many things to do, while the four surrounding countries glared at us like tigers watching its prey. If there was even the slightest misstep, the country would have been destroyed. That’s why the ruler had to pick a place that was hard to attack as a place to protect their life. The matter of excavating Xu Tian Cave was something brought up at that sort of time. The first few rulers of Da Shun did not live for long, so the matter of the throne was not something that was stable. That was why Xu Tian Cave continued to be worked on. It wasn’t until the fourth ruler was enthroned that the country stabilized, but matter of working on this place had become a habit and a conviction.”

　　Feng Yu Heng understood, “Xu Tian Cave had become a symbol. As long as this place was fine, the ruler would be able to feel at ease. It also represented the state of Da Shun. Now, Da Shun is the largest and strongest country. Now, there are large armies standing guard at the four borders. Even if there really is a battle with swords and spears being swung around, the ruler naturally will not think to visit Xu Tian Cave. Thus this place became yours, right?”

　　Xuan Tian Ming corrected her: “It became ours. I chose to handle the production of steel here. I fear that in the coming days, this is where you will spend most of your time.”

　　Feng Yu Heng laughed, “Not bad, I like this place.”

　　While they spoke, they had arrived at what the soldier had called the forge. It was an individually constructed space with a small path connecting it to the main cave. Following the small path, there was a smaller cave.

　　It was a smaller cave but only in comparison to the larger cave outside. In truth, this cave was not small at all. Based on Feng Yu Heng’s calculations, this place was at least 200 square meters. There were countless holes in the walls, and someone had already installed an iron-making furnace.

　　Qian Li clapped to the people in the forge then loudly said: “Everyone come over here. Come greet our general and county princess.!”

　　Everyone knew that the general of the Northwest Army was the current Emperor’s most favored ninth prince. Everyone also knew that county princess Ji An was the ninth prince’s future princess. Apparently, she was an even better divine doctor than her maternal grandfather, Yao Xian. Something that even more people knew was that county princess Ji An was the only person in Da Shun capable of producing steel.

　　Thus the 16 blacksmiths and the apprentices that they had brought along all came forward upon hearing that they had arrived. They all kneeled to greet them, saying: “Long live your Highness and county princess!”

　　This was the first time that Feng Yu Heng had heard people add her to the list of people being wished a long life. For a while, she was not very accustomed to it. Xuan Tian Ming naturally could not be more accustomed to this scene. Raising his hand, he said: “Everyone may rise!”

　　Everyone stood up with trepidation. Feng Yu Heng looked at these blacksmiths. The majority of them were advanced in their age, while the youngest looked to be at least 45 years old. As for their apprentices, they were all very young and only looked to be in their teens.

　　She then examined her surroundings. There were a large number of tools next to the furnace. There were large bellows, and there were piles of wood charcoal and iron charcoal. They were blacksmiths, after all. Everything prepared was to produce iron, but the tools that they had brought were very thorough and very professional.

　　She took the initiative to speak, asking them: “Do you know why you have been brought here?”

　　The blacksmiths all nodded, replying: “We do. We have come to produce something called steel.”

　　A slightly more bold one asked: “I heard that the thing called steel is extremely hard and can cut through iron as though it was mud. Is that true?”

　　He asked, and everyone had expectant expressions, waiting for Feng Yu Heng to reply.

　　However, she deliberately did not respond immediately. Instead, she used this opportunity to inspect their gazes. Looking at all 16, she nodded in satisfaction. They were indeed the best blacksmiths. Although she had not seen their work, this sort of pure enthusiasm for a new thing was not something that could be faked. Only someone with a sufficient degree of love for their profession could express this sort of attitude when told that there was an improvement that could be made. These blacksmiths were all this sort of person.

　　She slightly calmed herself. When it came to producing steel, what she feared were people with skill but no enthusiasm. In this era, nobody had ever experienced real steel. When starting out, it was very possible that the first 10, 20 or even 100 attempts would be failures. It was possible that without conviction and perseverance, it was impossible to develop this personality and could not handle this sort of suffering. These were the types of people that she wanted. Even if they were a little lacking in talent, she could slowly teach them a little at a time. As long as enthusiasm still existed, anything was possible.

　　She told them all: “To say that it can cut through iron as though it was mud is an exaggeration, but there are indeed many differences between steel and iron. Steel is a metal that is harder than iron. From a theoretical standpoint, steel is considered an alloy, while iron is an individual element. The main difference between the two is the carbon content. Put plainly, steel is just metal that has a certain amount of carbon content with iron as its base. If I say it like this, it is possible that you may not understand very clearly.” She said this while handing her steel dagger to Bai Ze, “Bai Ze, allow everyone to try it out. Let them understand where the difference is between steel and iron.”

　　Bai Ze very happily received the dagger and stepped forward; however, he heard an older blacksmith suddenly call out from the group: “Wait a moment!”

　　¹: Yu Gong is a man that is said to have moved mountains through hard work and perseverance. https://en.wikipedia.org/wiki/The_Foolish_Old_Man_Removes_the_Mountains