After Yin Jiuchen's meridian problem was solved, everything was back on track, and there were many things waiting for him to do.

The first is the reward for finding the Flame Crystal Mine.

Yin Jiuchen stood in front of the library, a retro wooden building with a total of seven floors, and the books inside were all books related to cultivation.

The library is an extremely important place in the school, and there are high-level teachers who handle it, but the building on the ground is only used to hide people's eyes, and all the books placed in it are relatively basic, and students can view them at will. The underground is where important martial arts and cultivation techniques are preserved.

Yin Jiuchen took the special sign, and under the leadership of the teacher in charge of registration, he came to the back of the library building, in front of a heavy stone door, he pressed a few times on the wall irregularly, and with a slight vibration and roar, the heavy stone door rose upward, revealing the narrow hole behind the door.

"Go in, there's someone inside. The teacher in charge of registration gave him a token engraved with the word "di" in red, and below it was a bar.

"Good. Yin Jiuchen clenched his fists in thanks, and walked along the dark passage towards the underground. The long staircase rotated down, and after Mo was about a hundred zhang deep, he entered a wide passage, and the lights under the passage were bright, and Yin Jiuchen saw a familiar person.

Yun Xiao and Yun will kill.

Also, the vein was discovered by the three of them together, and there was no reason why he was the only one to be rewarded.

There was some heat in the passage, and Yin Jiuchen was still wondering why this was the case, when an old man he didn't know came to him, raised his eyes and looked up and down.

Yin Jiuchen felt that he had been seen through.

"Nice seedling," the old man complimented, "where's your token?"

"Here it is. Yin Jiuchen took out the token that the teacher had taught him.

"Well, it is allowed to learn low-level martial arts, it seems that the three of you are the same batch of rewards," After confirming that it was correct, the old man turned and walked forward, "You follow where I have stepped on, be careful not to step on the wrong one." ”

"What happens if you step on the wrong step?" asked Yun Bi Duo Xin.

"There will be many ways to die. The old man replied lightly, and regardless of whether the three of them could follow or not, he walked straight forward.

The three of them didn't dare to be distracted and asked again, and hurriedly followed with their front and back feet.

This wide passage is not long, about 100 meters, and it can be seen that it is hand-hewn out on both sides of the bright lights, so that visitors can see the stone slabs on the ground.

Presumably, there were mechanisms connected to some stone slabs, and Yin Jiuchen was careful to step on the old man's footprints. Compared with the old man's leisurely stroll, the three of them seemed to be walking on a single-plank bridge.

Trembling and trembling, he walked through the big passage that was not long this day, Yin Jiuchen followed the old man to the edge of a cliff, and looked down at the cliff, the hot magma was steaming, and the fire rose to an extremely high level, distorting the air, and Yin Jiuchen knew why it was hot in the passage.

Above the lava, a stone bridge runs through both sides of the cliff, and the bridge is so narrow that only one person can pass through. If someone invades here, unless they can ignore the scorching heat rising and jump dozens of feet away, they can only obediently walk across this bridge one by one.

"Teacher, we can't bear this anger, right?" Yun Bi Kill looked at the distorted air, and felt that his clothes were about to catch fire as soon as he walked in.

"Don't worry, the stone bridge is protected by a formation, keep up, don't fall down with weak feet. The old man didn't look back, but continued to move on.

Trembling across the stone bridge, the four of them finally came to the place where the books were hidden, and there was another old man on duty here, but he only opened his eyes and glanced at the four of them, and closed them again.

The important books of the academy were all placed on the underground magma, among the hewn rocks, Yin Jiuchen raised his head, and could see several large characters carved on the entrance: Fengshan Library.

This is the real library of Maple Mountain!

Walking into the door, it is a very large place, all kinds of books are placed everywhere, no one has sorted them out at all, and some of them can see the names of the book covers when they are close, such as "Reflections on the Spiritual Law Realm", "The Price Method of the Tribulation Realm", "The Codex of the Study of the Gods", ......

Each one of them is very careful!

"Come with me, and be careful not to touch anything here. The old man reminded him indifferently, and he had already guessed the thoughts of the three of them.

Needless to say, Yin Jiuchen could also feel that these books were shrouded in a very tricky aura, and with his current realm, he couldn't break through at all, so he could only withdraw his thoughts.

In addition to the hall, there are dozens of small rooms that have been chiseled, obviously for classification and storage, before the old man took them to a small room, he waved his hand to disperse the protective aura, and said to the three of them: "This cave is full of low-level martial arts, you choose a jade slip to take away." ”

In the small space, dozens of jade slips were placed, which shows how abundant the resources of the academy are. There was a piece of paper next to the jade slip to explain the situation of the martial arts.

"Earth Secret Arts", "Whale Shark Collision", "Sky Sound Thunderstorm", ......

All kinds of powerful martial arts dazzled Yin Jiuchen, although Yun Xiaoyi and Yun Bi Kill are everyone's children, but their cultivation has not reached a certain level, and they can't get in touch with too many high-level martial arts, and they are also very excited at this moment.

When there are too many choices of martial arts, it is difficult to choose, and Yin Jiuchen chose one of them for a long time.

"Ground-level low-level martial art: Sword of Damnation. ”

This is a martial art that is extremely difficult to release for the Imperial Qi Realm, using his own will to communicate with heaven and earth, summoning an illusory giant sword that falls from the sky, and the actual attack power is comparable to the intermediate martial arts of the ground level, but the difficulty is too great, and it is judged to be a martial art that can only be released by the Spirit Law Realm.

Yin Jiuchen has his own considerations for choosing this skill. He has a low-level martial art "Vortex Slash", which can be described as extremely powerful in attack and defense, but this skill also has weaknesses, first, the Vortex Slash is a relatively passive martial art, only by absorbing the opponent's attack skills can it stimulate its terrifying slash, if it is not absorbed, the force of the slash will be much weaker;

In view of this, Yin Jiuchen chose the "Sword of Damnation", which is the strongest of the martial arts here, comparable to the power of the intermediate martial arts of the ground level. "Others may not be able to communicate with heaven and earth in the Imperial Qi Realm, and it is difficult to release this martial art, but Yin Jiuchen is different, when he has practiced outside the school, he can already communicate with heaven and earth slightly, and the possibility of successfully releasing this skill is still very high.

After choosing, Yin Jiuchen and the three of them showed the old man the selected martial arts, so that he could put the new jade slip in.

The old man looked at it, Yun Xiaoyi and Yun Bini made a decent choice, and when his gaze moved to Yin Jiuchen, he paused: "Are you sure you want to choose this?"

"yes, what's wrong?"

The old man thought for a while, shook his head, and reminded: "This is a killing technique, use it with caution." ”

Yin Jiuchen didn't understand what the old man meant, so he could only nod his head.