Chapter 863: The Secret of King Qin’s Mirror of Souls

“Linear algebra?” Zhao Ruizhi frowned. He didn’t even have time to feel anger. He thought, What kind of secret manual is this? Why haven’t I heard of it before?

Forget about him, even Mi Li, who had read through the entire Qin Royal Family’s library, was stumped. What the hell is linear algebra? Why don’t I know what this is?

Only Bi Linglong seemed to have picked up on something. She recalled that according to Zu An’s information, he seemed to have been Brightmoon Academy’s mathematics teacher. Furthermore, when he had made a trip through the Royal Academy, even those revered teachers had been left in awe of his knowledge. This ‘linear algebra’ was probably one of the special skills he had.

Zu An confirmed the stele inscriptions with Zhao Ruizhi one more time, and then he muttered to himself, “‘Dark clouds’ should be matched with ‘Heavenly Gate’; this describes our situation when we first arrived on this island…”

But the latter parts involved ancient astrology, so Zu An didn’t understand it too well. Still, for better or for worse, he had a well-read granny with him. He asked Mi Li for help. That way, he gained a rough idea of the steles’ secrets.

The ‘Heavenly Gate’ was located in the corner of the twenty-eight constellations; the ‘great sun’ was naturally the sun itself. The ‘Golden Palace’ historically referred to the palace courtyard where heaven and earth resided, while the Purple Forbidden Enclosure of the ancient celestial bodies was a residence within heaven and earth.

Ancient astrology divided the heavens into three enclosures and twenty-eight constellations. Those twenty-eight constellations were arranged in groups of seven, and those groups were divided into north, south, east, and west through the Azure Dragon, Vermilion Bird, White Tiger, and Black Tortoise.

The ‘Southern Star’ most likely referred to the Sagittarius star; the Southern Star moving around the Alioth should have been quite the rare phenomenon according to normal astrology, and that was what had left the emperor in despair earlier. But these slabs corresponded to the heavens, and he just had to match them all up. They didn’t really need the specific astrological phenomena.

The ‘Imperial Canopy’ referred to the Purple Forbidden Enclosure’s Imperial Canopy star; ‘purple’ referred to the Emperor star.

‘Elegant music’ in ancient times referred to Xia music, and the Xia people were descendants of Xuanyuan. That meant it referred to the Xuanyuan star. ‘Zheng’ referred to the Heavenly Market Enclosure’s Zheng star.

With Mi Li’s help, Zu An quickly cracked the secrets of the inscriptions. He just had to match them up to their proper positions.

This type of pillar rotating puzzle wouldn’t be too difficult to brute force if it were a simple one, but a mechanism as complex as the stele inscriptions made random testing pointless. But even though the ancient puzzle was quite profound, it wasn’t too difficult for someone like him who had a college education. It was merely a linear algebra problem.

𝚏𝐫𝚎𝗲𝕨𝐞𝐛𝕟𝚘𝐯𝚎𝗹.𝕔𝐨𝗺

He gave each pillar a number, then recorded how the others spun according to the first pillar’s rotation. For example, if the second pillar didn’t spin, it would be 0. If the third spun once, it would be 1. If the fourth spun twice, it would be 2, and so on. He could then remember it as d1=[1,0,1,2…]t.

Then, if he turned the first pillar x1 times, the pillar would become x1*d1. If he spun the second pillar x2 times, the pillar would become x2*d2. From there, the final pillar would be x1*d1*d2+x3*d3+…=b. b would be a constant; since they had the exact final positions from the stele inscriptions, he could deduce the final state of the pillars and how many times each pillar had to be rotated.

The sequence would then produce a homogeneous linear equation, and x1, x2, x3… could all be solved. These would tell him how many times he had to spin each pillar, thus granting him the final state the stele inscriptions presented.

Zhao Ruizhi was completely lost as he watched Zu An write out symbols he had never seen before on the ground. He couldn’t help but give the others a few glances. He saw that whether it was Bi Linglong, He Li, or anyone else, they all appeared stupefied, making him feel a lot better.

A while later, He Li couldn’t help but sneak a look at the emperor. He saw that the emperor was nodding slightly as he watched Zu An draw those weird symbols, as if it were making sense to him. He immediately felt admiration. His majesty is his majesty after all; he can even understand these things!

Zu An finally stood up after a while. “It’s done!” Then, he walked over to the stone slabs, spinning the pillars according to the answers he had calculated. Sure enough, all of the diagrams matched after he rotated them in order!

Another rumble emerged from underground as the mechanism began to activate. The stone slab mechanism lit up. Then, the light rose, illuminating the luminescent pearls Zu An had placed in the holes before. Rays of light shot out from the luminescent pearls, striking certain parts of the stone slabs. Those slabs then tilted slightly.

But nothing much happened even after those present waited for a while. Zhao Ruizhi frowned. “What’s happening?”

He wasn’t in a rush to criticize Zu An, because various signs had proven that Zu An’s method was the right one. Were they still lacking something? He couldn’t think of anything, so he looked at Zu An. As an emperor, he didn’t have to do everything himself. He could just hand over his headaches for his subordinates to think about.

Zu An was also confused. Hadn’t he already done everything properly? Why hadn’t anything happened?

Mi Li suddenly thought of something. “Do you still remember the last line on that stele we saw?”

“The noble lunar moon at the center…” Zu An silently mouthed those words. He saw a slight depression where the beam of light struck the slab. The depression’s shape resembled a mirror. He thought of something, and took out King Qin’s Mirror of Souls, something he had obtained from the Jade Moon Serpent. Sure enough, the shape matched perfectly.

Zu An had tried all sorts of methods to activate it ever since he obtained the mirror, but it had never reacted to anything. But now, when the light hit the mirror, it seemed to come alive. It lit up like a small sun, becoming so dazzling no one could look straight at it. A streak of brilliant light shot out from the mirror, firing through the clouds and landing somewhere on the third sacred mountain.

Then, something shocking happened. An extremely wide, bright yellow light slowly descended from the sacred mountain. It unfurled like a carpet, and soon reached the second sacred mountain. Afterward, a similar carpet of bright yellow light emerged from the second mountain, traveling toward where the group was. It quickly stopped near the stone slab array, forming a transparent bridge of light between the islands.

After the bridge formed, the light coming from the luminescent pearls in the stone slabs gradually disappeared. King Qin’s Mirror of Souls also returned to normal. Zu An quickly put it away, as it was an absolute treasure he couldn’t afford to lose.

Zhao Ruizhi gave him a look. He could tell that the mirror was special too. He had just been about to take it and eliminate Zu An, but he remembered what Zu An had said earlier. He had even witnessed Zu An’s skills with those weird symbols, so the brat might really be skilled with such puzzles. As such, he decided to wait for the time being, because in the future, there really might be situations where he needed Zu An.

After calming down his killing intent, Zhao Ruizhi was the first to step onto the bridge of light. He was careful at first, but he soon discovered that even though the bridge looked transparent and terrifying, it was like walking on sturdy ground. There was no need to worry about falling off.

“Is this one of the so-called methods of an immortal?” Zhao Ruizhi’s eyes burned with passion as he stared at the distant palace. His figure turned into a blur and he quickly arrived on the second island. He Li and the others quickly followed behind him. After all, there might be tremendous opportunities related to immortals up ahead. Who didn’t want a share in that?

Zu An cried out pitifully inside. He had wanted to try and see if he could use the bridge of light to kill the emperor, but whether it was the pearls or the pillars, they were all firmly set in place. He couldn’t move them at all. “Forget it, I’ll look for other opportunities,” he muttered as he brought Bi Linglong onto the bridge as well.

Bi Linglong was incredibly shocked. She looked around excitedly as she walked on the bridge of light. However, Zu An had already seen similar scenes in the shows and games he had played, so it wasn’t all that special to him.

He silently brought out the Mirror of Souls. It seemed to have been activated earlier. Does it have any abilities now? he thought. But unfortunately, it remained lifeless the entire time. He didn’t notice anything special about it. “Did I just misunderstand?” he muttered, frowning.

While Zu An was holding the mirror, Bi Linglong just happened to be standing behind him, looking at him in puzzlement.

Zu An lowered his head to look at the mirror, and blood immediately trickled out from his nose.