Castle of Black Iron

Right outside one of the 81 entrances of caves, Zhang Tie saw the same mark. However, this entrance was emitting a hot flame as high as dozens of meters while being surrounded by a lot of knights. They appeared to be waiting for a proper moment to enter it. The moment Zhang Tie and Bai Suxian arrived, a knight from Lord Guangnan's Mansion who had long been waiting here flew towards them.

"Princess, Guye, I, Bai Yuanan, have been waiting for you..."

As the relation between Zhang Tie and Bai Suxian had been fixed, all the myrmidons and knights in Lord Guangnan's Mansion called him Guye instead of Qianji Immortal as the former one sounded more intimate.

Zhang Tie had indeed seen this knight in the banquet two days ago. He was a myrmidon of Lord Guangnan's Mansion. Bai Suxian's third uncle was in the hole. After being told that Zhang Tie and Bai Suxian were coming, he especially had a knight wait here for him.

"Can we access to the underground space through that entrance?" Bai Suxian asked as she pointed at that crater.

"Yes, we can!" Bai Yuanan said as he nodded, "There're 81 craters. Previously, someone had already searched over here; however, they didn't imagine that the access to the Dongtian of Great Wilderness Sect is one of these craters..."

"Only one?"

"Only one. As for the other 80 craters, even if the flames stopped for the time being, people would die for sure inside; except for this one, when the flames stopped, people could rapidly rush in. After reaching greater than 20,000 m underneath the crater, people would see 9 bypasses, only one of which is safe; all the others are dead ends. As long as one goes the wrong way, one would perish when it emits flame again, even if he is a knight!"

"Aah, that sounds so precarious!" Bai Suxian took in a deep breath after hearing the knight's introduction.

"Each one hour would permit two minutes' interval, during which period people have to enter it if they want. Because it's a bit perilous here. Third lord especially had me stay here to lead you the way lest any trouble!"

Hearing Bai Yuanan's words, Zhang Tie started to observe these craters using his lotus-flower eyes.

From the ground, he saw 81 entrances; however, when his vision entered those entrances, he found almost every cave has complex and dense bypasses when it reached 10,000 m underground, which were like roots and stems of underground old trees. The deeper it was, the more complex the bypasses would be. Many bypasses were linked with each other. After a short glance, Zhang Tie had seen at least tens of thousands of bypasses within tens of thousands of meters vertically, only one of which was correct.

Therefore, it was the best way to protect the secret. If people didn't know the correct route, it was almost like seeking for death inside the entrance.

However, as Zhang Tie's vision reached further and deeper, Zhang Tie gradually had an erratic feeling——there's an integral piece of bizarre metal underground while those flaming tunnels inside this metal reminded Zhang Tie of human's lung. The tunnels emitted flames every once a while as if a huge lung was breathing.

The mother nature's marvelous craftsmanship was awesome.

"How did people discover it?" Zhang Tie asked Bai Yuanan.

"It's four sage freaks of South Border who discovered this place."

"Four sage freaks?"

"It's their nickname..." Bai Suxian answered as she added, "Four sage freaks refers to four black iron knights who gathered together because of common interest. They were one group of freaks in South Border. Although the others called them four sage freaks, they call themselves four sage intelligentlemen. They're respectively Mr. Plum, Mr. Orchid, Mr. Bamboo and Mr. Chrysanthemum..."

After Bai Suxian's explanation, Bai Yuanan added, "When the Great Wilderness Sect existed, the four people befriended an elder of Great Wilderness Sect and knew something about Great Wilderness Sect. After Great Wilderness Sect was exterminated, the four people are most interested and active in discovering the Dongtian and treasures left by Great Wilderness Sect. Over these years, although they failed to discover the Dongtian and treasures of Great Wilderness Sect, they indeed have discovered some places associating with Great Wilderness Sect such as courtyards and secret caves of Great Wilderness Sect in South Border. This time, nobody knows how the four people knew the secret access to the Dongtian of Great Wilderness Sect. They stealthily came to Centralpolar Mountain; however, they didn't imagine that they had long been followed by their opponents. After following them in, their adversaries didn't gain any benefit; instead, they suffered a loss; therefore, after exiting the tunnel, their rivals exposed the news to the public as they obviously didn't want the four sage freaks to enjoy the benefits alone. Otherwise, nobody else could have known this secret..."

"What's the situation inside?"

"Mr. Bamboo has already entered a tower of time. The other three people are just guarding outside. These days, all the major sects and clans had already assigned people here. Therefore, it's a bit sophisticated downside there..." Bai Yuanan said. Finding the flame was gradually fading away, he added hurriedly, "The moment the flame dies out, we should enter the entrance. We only have a few minutes. If we miss it, we have to wait for another one hour..."

"Hmm, let's move closer..."

After reaching the crater, the three people only waited for less than one minute before the white flame died out. After another 10 seconds, all the knights outside the crater flew inside hurriedly.

The diameter of the crater was over 30 m. Although the flame had already died out, the temperature inside was still very high. It took Zhang Tie, Bai Suxian and Bai Yuanan about 2 minutes in reaching almost 20,000 m downwards when they saw 9 bypasses. Bai Yuanan then flew into one bypass, followed by Zhang Tie and Bai Suxian, the other knights. Only after all of them entered that bypass for 30 seconds, the white flame had reappeared behind them, filling all the tunnels behind them again...

If it took them half more minute to come here or they went the wrong way, they would perish at a stroke. Some knights really oozed sweet all over.