Castle of Black Iron

Zhang Tie followed the old man all the way up the mountain along the stone trail. Besides beautiful scenery, Tigerback Mountain also had plentiful reiki. Right beside the stone trail, there was a crystal brook, inside which giant salamanders, mossbacks and fish could be seen everywhere. There were also dense woods beside the stone trail. Monkeys were jumping over treetops every once a while. Birds twittered from time to time. Zhang Tie looked around as he nodded inside, 'This is indeed a nice, inhabitable place.'

Only after 10 more minutes, the two people had already come to the hillside of Tigerback Mountain where Zhang Tie saw a large complex. Additionally, many people were busy working here. Someone commanded some subordinates to carry a huge winnowing pan with a diameter of 1 m out of the room and air the contents inside bamboo winnowing pan in the square.

Some rooms were filled with steam, which indicated that people were boiling herbal medicine inside. Some rooms were reflected with flames, which implied that people were cooking medicinal pills inside. Zhang Tie could sniff various herbal medicines and medicinal pills.

Those people ignored Zhang Tie as they just paid attention to their own jobs. With the guidance of the old man, Zhang Tie came across two colorful herbal medicine gardens before coming to a relatively tranquil place. After leading Zhang Tie into a parlor and having people serve a cup of tea for Zhang Tie, the old man asked Zhang Tie to wait here for a short while. He then took Zhang Tie's item to Bian Heng. If Bian Heng agreed to meet Zhang Tie, he would come here; if not, the old man would return Zhang Tie's item back to him and walk him off the mountain.

Zhang Tie nodded. He then sat in the parlor while drinking the aromatic tea, waiting for Bian Heng.

Zhang Tie believed that Bian Heng would come here to meet him. If Bian Heng was an average person, he might not meet him; now that Bian Heng was a sage-level knight, he would come here for sure because Zhang Tie gave the old man a gold coin, a wholly new, common gold coin produced in Taixia Country.

There was neither gold nor gold coin in Motian Realm. Therefore, that gold coin carried a lot of information and was of great significance. As for ordinary people, a gold coin might not count at all as it was not edible; however, that gold coin carried a great significance for these people on the top of Motian Realm. The same item meant different for people on different levels.

Even immortal emperors were interested in that gold coin, Zhang Tie didn't believe that Bian Heng wasn't. Otherwise, the so-called Bian Heng the Yama was short-sighted.

As he sipped tea, Zhang Tie started to release his spiritual energy to sense the surrounding situation.

After the old man left the parlor, a wisp of Zhang Tie's spiritual energy followed that old man through the winding corridor beside the parlor, the courtyard, then to the front of an attic, where the old man knocked at the gate.

"Come in..." A slightly dry sound came out of the room.

The old man entered the attic, closely followed by Zhang Tie's spiritual energy...

Under the gaze of Zhang Tie's spiritual energy, he saw that a short small-eyed aggressive person with messy silver hair and flat bulbous nose was writing something on a piece of paper with a painful look by a writing brush.

'Is this average-looking, even a bit funny old guy the famous Bian Heng the Yama across Motian Realm?'

Zhang Tie became slightly shocked.

However, even though Bian Heng was a sage-level knight, he still didn't find that Zhang Tie's spiritual energy had already slowly invaded into his attic and was watching him silently from a viewpoint.

It was messy inside the room. The walls, the desk and the ground were full of papers being covered with figures, line segments of different lengths and squares.

"Master, a person brought you an item..."

The old man's first sentence unraveled Zhang Tie's doubt. This unkempt man was indeed Bian Heng the Yama. The old wind immortal general was just Bian Heng the Yama's servant.

"Did someone ask me to give him favor in the name of an immortal emperor or king of an immortal palace again?" the unkempt old man asked as he continued to watch those figures on a piece of paper with a frown. Meanwhile, he waved his hand impatiently and roared, "Let him roll out of here. This father doesn't want to waste time on them. Except for Star Emperor or Force Emperor, drive all of them away..."

The old servant didn't say anything as he just put that gold coin on the desk of Bian Heng the Yama lightly.

In the beginning, Bian Heng didn't notice it. However, when he glanced over that gold coin, he became shortly stunned. Closely after that, he put down his ink brush and picked that gold coin. After looking at it for a while, he gradually turned serious.

This gold coin was different than that which Force Emperor gifted Dragon Emperor in style. However, they were both stand gold coins in Taixia Country. The positive pattern of this gold coin was a slender maid who was playing the zither while its back was the image of the magnificent headquarters of Xuanyuan Bank.

"Who... brought this item?" Bian Heng asked as he gazed at the delicate patterns and the characters on the gold coin.

"A young man at his 20's given his look!" the old servant answered calmly.

"Did he come from an immortal palace?"

"I guess not. That young man came here alone. He has a poor battle strength. I don't know his real power..."

Bian Heng became shortly hesitant. After glancing at the gold coins for another a few times, he finally stood up and said, "Well, I'm going to meet this young man..."

After leaving the words, Bian Heng strode out of the attic. The old servant closed the gate of the attic and followed him away.

Zhang Tie's spiritual energy still stayed in the attic. He found some patterns on the walls of the room which looked like deductions of eight diagrams and some lines and figures that Zhang Tie didn't understand. Zhang Tie could only understand some 9 square patterns, 16 square patterns and 25 square patterns which were traditional patterns among Hua people.

Mathematically, a 9 square pattern was a trimagic square; a 16 square pattern was a quadramagic square; a 25 square pattern was a pentamagic square...

Zhang Tie saw some septuplemagic square on the walls. Just now, Bian Heng was struggling for drawing an octuplemagic square on the desk just now. Most of the balls of wasted paper on the ground were false octuplemagic squares and various calculations.

'What was Bian Heng the Yama doing here?'

Watching various patterns and figures in the room, Zhang Tie became muddle-headed...

However, there was on point that Zhang Tie could confirm that the so-called 9 square pattern was just a simple terminology; actually, it had another name Luo Book. It was said to be a secret item left by deities. As the foundation of 5 elements and the source of mathematics, it contained endless secrets...