Tang Dynasty: Starting at Xuanwu Gate, this prince is better off not being one.

"I brought this out to present to you," Li Yu said.

"I know. You just said it's used in battle, tell me how it's used?" Li Er smiled happily, even interested in testing Li Yu.

Li Er knew exactly how to use this thing, so Li Yu's answer was simple: "Naturally, it's used in the same way as dealing with Li Chengzong. However, compared to sticks, bows and arrows are more suitable."

"First, obstruct the enemy's line of sight, then unleash a volley of arrows; the effect should be excellent."

"Not bad, not bad! You're quite clever, kid."

Li Er praised twice, then his expression suddenly turned serious: "The year you disappeared was the year before His Majesty ascended the throne. Since then, His Majesty, I, and your father have searched for your whereabouts countless times, but all to no avail."

"Later, His Majesty sent his secret service, and I also dispatched the Hundred Cavalry to search for you two years ago, but we still didn't find any news about you. In the end, it was your father who found you in the territory of Tuyuhun. At that time, you still looked like you were mentally impaired."

"So even now, I still haven't asked you where you were for the past eight years, or who taught you these strange and unusual skills. Think it through before you speak!"

At this moment, Li Er was extremely serious, his eyes fixed on Li Yu's face, waiting for him to speak.

I finally asked this question.

Li Yu felt sorrowful. He couldn't talk about the time travel, nor could he fabricate anything too mythical.

Ultimately, in this era of absolute imperial power, legends of gods could emerge, but the existence of gods was absolutely forbidden. If any person or event arose that was beyond the control of the imperial power, that person would either be imprisoned for life or chopped up and fed to the dogs.

Fortunately, Li Yu had already prepared his explanation: "In reply to Second Uncle, I dare not lie. From as far back as I can remember, I was taken by a wandering old Taoist priest to a place called Byzantium, which is what we commonly refer to as 'Fulin'."

"Fulin? That place is indeed beyond the reach of the Hundred Cavalry Division." Li Er stared at Li Yu's face, seemingly searching for a flaw in his expression.

Unfortunately, Li Yu had already rehearsed this scene in his mind hundreds of times, so even though Li Er stared at it for a long time, he couldn't figure it out.

So he could only continue asking, "Why did the old Taoist bring you here? And how did you end up in Tuyuhun?"

The ointment on his buttocks had hardened into clumps, making it extremely uncomfortable. Li Yu tried to scratch it, but Li Er slapped it away.

So he could only move slightly and continue, "The old Taoist said that my identity was special and I could not stay in the Central Plains, so he brought me here."

"As for the boy's language, literacy, and the things he has researched, he learned them all from him."

"In the following years, he traveled to other countries there, and finally came to the Abbasid Caliphate. However, the old Taoist priest was old and died there not long after arriving."

"So I followed the Arab caravan back to the Great Zhou, but before I even reached Chang'an, I was taken away by a group of Tibetans somewhere..."

To ensure the story's authenticity, Li Yu didn't go into too much detail; too much detail would only create more flaws.

For example, things are fine as they are now. Li Er stopped dwelling on his past experiences and instead focused his attention on Byzantium, far to the west: "Boy, I've only ever heard of Fulin. Almost no one from the Central Plains has ever been there. Tell me, what kind of place is it?"

Li Yu pretended to recall for a moment and replied, "The language, culture and architecture of that place are very different from those of the Central Plains. At its peak, even the ocean was just an inland lake for them."

"However, it is now showing signs of decline, and its national strength is not as good as that of the Great Zhou. But I heard from that old Taoist that their navy is very powerful, and they are also rich in glass."

"Glass? This is a good thing."

Li Yu's story made Li Er fall into deep thought. After a long while, he asked Li Yu, "What benefits do you think I would gain if I led troops to fight there?"

Upon hearing Li Er's shocking remarks, Li Yu struggled to suppress the urge to roll his eyes.

You want to fight in Europe? You should take down Korea first...

While inwardly complaining, he had to maintain a friendly demeanor: "You'd better not lead your troops there. Forgive my bluntness, but you won't gain anything..."

"How so?"

Li Yu shifted his position again and continued, "At such a distance, even if you led 500,000 troops, I'm afraid it would be difficult to conquer that place."

"Furthermore, if you want to bring 500,000 troops to Fulin, you must first occupy the Four Garrisons of Anxi, then the Nine Sogdian States, Persia... By the time you get there, you'll probably only have about 20% of your troops left. Even if you eventually conquer Fulin and then control the surrounding countries, you'll gradually lose control of them due to the distance and difficulty of reaching them..."

Listening to Li Yu's logical analysis, Li Er couldn't help but admire his third brother, who was only a fierce general who could only charge into battle, actually had such a clever and shrewd son.

In contrast, although his sons were all outstanding among their peers, they were inferior to Li Yu.

Seeing that Li Er remained silent for a long time, she assumed that he was reluctant to part with the glass and secretly despised him in her heart, but on the surface she comforted him and said, "Actually, Uncle, if you really want the glass, it's simple. That pile of things is just made of sand and fired. It's nothing special except for its appearance."

Originally, Li Er wanted Li Yu to continue talking about other places, but upon hearing what he said, Li Er exclaimed in surprise, "Kid! Really? You're saying those priceless glass pieces were made from a pile of sand?"

"That's right! The reason our glass is expensive is simply because the firing method is too crude and the technology is not mature, so the probability of producing a finished product is low. Once the right method is found, glass may even become so cheap that it appears in buildings or in the homes of ordinary people."

Li Er was so shocked by Li Yu's words that he couldn't sit still any longer. He stood up and looked down at Li Yu, asking, "According to you, you can make cheap glass?"

Suddenly realizing he might have gotten a little too carried away, Li Yu chuckled awkwardly and said, "This nephew doesn't know..."

Snapped! ! !

Enraged, Li Er slapped Li Yu on the back of the head, then pointed at him and roared, "You...you brat, you talked on and on for ages, but it was all just empty talk! You good-for-nothing! You scoundrel!"

Huh? How did I become such a fool?

Seeing Li Er's furious expression, and even his eldest grandson glaring at him with anger, Li Yu felt like crying: "Please, both of you, let me finish!"

"Although I don't know how to fire it yet, just give me some time, and I'm sure I can figure out how to fire glass based on the existing records..."

"Is that really so?" After hearing Li Yu's explanation, Li Er's anger gradually subsided, and he asked with some doubt.

"Of course, how could I dare to lie to you two!" Li Yu exclaimed, feeling utterly wronged.

"That's more like it... wait a minute!"

Li Er was speaking when he suddenly seemed to remember something, and asked with half-closed eyes, "I haven't asked you yet, how long is your 'sometimes'?"

"You're not going to wait until you've all passed away, then lie on your second uncle's grave and wail, saying you didn't figure it out, and that you'll do it in the next life or something?"

.........