The prince was stunned. In front of him was standing a two-meter tall grey wall that could pack a punch.

His lightning bolt had no effect on it and he had to use Chi to chip at it with a strengthened punch. His bodyguard was the only one able to punch a hole through it but he had to go at it three times while putting more and more Chi in his strike. He said it would be sturdy enough to hold off most monsters, those that could brute force their way through this wall would also not be hindered by the usual stone walls.

I had spent three days erecting dozens of low walls with my three options: sand-gravel-stone, brick core, pure concrete, multiplied by the number of samples of cement I had.

I had requested the archery range to have a place where to perform my experiments. I had a nice timetable with numbers and labels for each of my samples. It felt good to use the scientific method once again, it was both reassuring and nostalgic. I might be in another world but rationality was still a powerful tool.

Though I was sure some of my samples had a part of silicates, it wasn't enough for my cement to be hydraulic. My cement was hardening when drying, it wasn't the best outcome because it was taking far more time and couldn't be used to build bridges or harbours but it would make do for now.

I had one of the sturdy friends of Aruko stir the thing as I poured it with various mixes, using planks to shape the wall before waiting for more than a day for the reaction with the air to harden the mix. Luckily, the weather was on my side and it was dry and windy enough to help my experimentations. It was a crude work compared to what one could do with modern hydraulic cement but it was a good enough proxy.

A lot of my mixes were just bad. Either I put too much water or not enough but the end result was quite friable. Sample delo(13) had the best results, it was easy to mix with water and hardened after a day of exposition to the air to become hard as rock and smooth looking. One of the workers made a prayer sign to Arteus, praising the god's power.

It was no miracle, just the power of chemistry.

Sample delo had a few percent of clay added and contained more beaks of chogsus, bringing a bit more silicates into the mix. In time, I'll have to find a mineral source but hunting the tentacled manhunters wasn't making me sad for the time being.

The sturdiest wall was a mix of a core pillar of bricks drowned in cement with sand and gravels. Once hardened the thing was both rough looking like stone, resistant, and must have had some porosity inside. Those air bubbles were helping it disperse kinetic energy, making it both sturdy and “supple” enough to not crack at the first blow.

The real hard part was building a 2m tall portion of wall. This is where my employee shone.

Kirli was a thirty years old sturdy fellow. He was a former serv that had bought his “freedom” to become a commoner in our city. He had an unusual tanned skin that was not just the product of working outdoors but also the sign that he was stemming from mixed parenthood which often meant coming from the southern free cities. Which was indeed his case.

He had the biggest nose I'd ever seen, the fat bud was growing on his face, eating a third of it and he was desperately trying to hide it under the bushiest moustache a human could grow. It was like he was wearing one of those comical masks with a big nose and moustache made for carnivals.

Despite his rough looks and sturdy muscles, the man was resourceful and of a calm disposition. He would take a minute to consider what he had to do rather than blindly rush after my orders.

In fact, I wasn't ordering him much, he had dabbled in many occupations while trying to make whatever coin he could and had some experience in construction. Although not with cement, it still helped a lot when we had to lay bricks and find a way to build the 2m tall wall.

We build it by layers, going up as the cement was hardening and adding more on top right before it was becoming solid.

This required the two of us to stay near our wall at all times, watching out the state of hardening we were reaching and lay more bricks as soon as the liquid was becoming half solidified. We even worked overnight on the last day of the bet.

Of course, he was in for the money but he also was genuinely interested in the process and was a good wall to bounce ideas on. He was putting up with being led by a kid and had enough experience in construction to provide me with insightful returns.

* * * * *

“How long a wall can you make in a day's worth of work?” asked the prince.

I had no idea. I wasn't even sure of how much cement I could produce. “I'm not sure. With enough cement and workforce and if the bricks are already on site I would say as long as this archery range.”

This was about 200 meters. I still had a hard time with this world's measurements and was reluctant to speak in feet or arm-length. Would I be speaking of my arm or an adult arm? Would a Trollkin speak in troll arms and an Elve in elven arms? Who was to make sure an “arm” was of standardized length?

This sent the prince in a daze as he was figuring out what to do next. “If you can manage that in a day, we could rise a small nighthaven in a week,” he calculated, “I should be able to afford an expedition to protect the crew for the time doing. Are you sure this requires no magic at all or no Chi users of the second rank?” he inquired in disbelief once more.

“Yes, I'm sure,” I confirmed with confidence, “I've built this alone with commoners and none of us used magic nor Chi,” I bitterly explained.

It wasn't entirely true, Kirli was a second level Chi user, so in the lower part of the first quarter, according to him. That would put him on the same level as my dad, giving him a bit of extra workforce when needed but nothing herculean. What the prince was referring to were Chi users of the second rank: those that were level 5 to 8. This was the level of higher-ranking officers and quite strong Chi users. It was what was usually required to manipulate the huge rocks weighing tons that they would use for the construction of nighthavens.

With a whole crew of men like Kirli or perhaps a bit stronger, things could go really fast. They would just have to be wary around the cement to not get chemically burnt but otherwise, they should be able to lay the foundation fast. Even more so because the Nighthaven was a wrecked fort to fix up rather than a new one to build out of the ground.

“The real limit will be how much bricks and cement I can procure. I don't know much on the brick situation but for cement, I am limited in the number of kilns I can use and the amount of shells I can collect.” I explained to the lost-in-thoughts prince.

“I'll provide with what is needed and the military will support this,” he decided. “I need to talk with the Shieldlord,” he announced before leaving us in the archery range.

* * * * *

In the end, I was commissioned to build a wall.

Not only did I win my bet and earned myself a silver but I was “hired” to manage the production of cement.

I had more money available than I could spend, part of it was turned into bonuses for all the workers who helped, be it construction, kiln's crew, or fishermen. This ate half of my reward in a flash.

A court official was appointed to supervise me and help me with management. It would look bad for a kid to handle Shieldom business on his own.

My supervisor was one of my former students so it made things easier to get along with her. She was a young woman in her twenties. A free citizen who had the black hair of the Empire and always braid it in a crown around her head. She was chosen because she was smart, young, and the daughter of one of the military providers that didn't cheat on their prices.

Akili Mohio was her name. She was nice with me, respectful even but knew when to crack a joke to ease the mood going around our mismatching pair. She was cute with her delicate nose and had eyes as dark as onyx beads. I suspect the prince had a thing going for her and was doing her a favour here.

With her help, we made a huge turnaround in the fishing industry. Now that shells were worth something and asked in large amounts, fishermen and tridents were actively hunting chogsus and other beaked beasts. I was fearing that our supply will run out when they exterminated the population but won't regret the existence of the chogsus. I didn't forget the half-eaten body of the fisher's apprentice. Sure, removing an apex predator will imbalance the flora and fauna. We will have to monitor the situation with the help of Charavatkeh's priests to make sure the fish population was under control. Worst case scenario, we will have to fish more, which means more food. There would be other predators to fill in for the chogsus, but without hunting men.

The kilns were more of a bottleneck. I now had enough shells and even the miners were tasked to look out for limestone and gypsum. The problem was to process it.

The kilns were needed to provide coal to the denizens before winter, we couldn't impair this work. Once loaded with wood a charcoal kiln would slowly burn for a half hex. So the amount of free kilns we could ask for was limited.

Building more kilns would take time and we wanted the nighthaven to be ready before winter, we had to secure the area to stop monsters from settling in the plains during the winter and make nests that would impair farming in the next Spring.

With the help of Akili, I managed to secure four kilns for calcination. I had Siroz appointed as the foreman. I knew him, he was part of Aruko's family, was quick-witted enough and deserved the promotion. He was far from smart but he knew his job and looked diligent. If he ever slacked off, I would ask Aruko to beat some sense into him.

He put up a team of a hex men that were working around the clock to calcinate as much as they could. The pay was better than coal making and this allowed him to rope in the best workers around.

I've let Akili handle the bricks part, she simply had to negotiate with the traders in stead of the army and would do a better job than me. She knew the prices, the costs of manpower at this time of the year, and wouldn't be subject to scam attempts like the naïve-looking kid I was.

We were in Piscost, month of Charavatkeh, and had to hurry things up if we wanted the fort to be operational before winter.

While Akili was dealing with the logistic, perusing the costs and drafting the budget for me, I was training the workers with the help of Kirli.

We were using what little cement was left to train a makeshift crew of builders. A good chunk were servs belonging to the prince himself and the rest were commoners like Kirli that were trying to make a coin where they could. Only a few of them had knowledge about construction.

I think the prince was still testing my claim that I would only need commoners to manage the feat and was making things difficult for me. He was kind of a sore loser for just one silver.

The only help he would provide was the military escort to protect the construction crew.

With all this, I was still unable to work on gunpowder but hadn't forgotten about it. Thanks to my recent success and proof of the promises that my “chemistry” held, the old lord gave me back the niter and sulphur. For now they were stored in the room I was sleeping in at the palace's servant's wing. I also got his sigil back, mostly to make sure no one would dare abuse the kid I was while working on the project for the city.

The prince gave me his too but it just didn't hold as much power as the former lord's one even if he was the current heir to the Shieldom.

The workers' crew was making good enough progress under the supervision of Kirli. We were gonna build a wall.