The huge shock wave generated by the explosion knocked Gu Dawei upside down and flew up, and fell into the pond below him with a "bang".

Because Lu Zhan was standing on the ground, he was not affected by much of the explosion.

After being knocked into the pool by the shock wave, Gu Dawei was scrambling to fly out of the water, but the ichthyosaur in the water was already scrambling to bite its body, and in an instant it dragged him to the bottom.

Lu Zhan, who was standing on the edge of the pond, saw the masked man being dragged into the water by a group of ichthyosaurs and tearing frantically, large balls of blood came out of him, and the black cloth covering his face was also torn apart, revealing his true face.

"It turned out to be him, Gu Dawei!" Lu Zhan was stunned, he asked himself if he didn't have much grudge against Gu Dawei, although this person always likes to come to him when he has something to do, but there is no need to form such a big hatred, even to the point of plotting his own life?

Gu Dawei in the water struggled for a moment and then fell silent, his body had been bitten by the ichthyosaur to the bone, and the clear pool was also stained red with blood.

At this time, the big dragon loach saw that he couldn't win those fish and dragons in the water, and opened his mouth in anger and sucked wildly, and saw that the water level of the pond dropped rapidly, and in the blink of an eye, a pool of pond water was sucked into the belly of the big dragon loach, and the original rippling pond became a dry pond in an instant.

Those fierce and ferocious ichthyosaurs suddenly lost the help of water, and suddenly lost the ferocious and violent momentum they had just descended, and hundreds of colorful ichthyosaurs lay listlessly on the dry riverbed, and Gu Dawei's corpse had become a white skeleton at this moment.

Lu Zhan looked at the ichthyosaurs and big dragon loaches lying on the riverbed, and his heart suddenly moved, when will he not accept them at this time?

He straightened his stomach, and a colorful glow flew out of his belly, and in the blink of an eye, he included the hundreds of ichthyosaurs on the riverbed, along with the big dragon loach, into his cave.

After collecting these ichthyosaurs, Lu Zhan's task of finding quenching materials for this trip was completed. He quickly walked back the way he had come. Passing through the swamp and over the mist-shrouded area, it didn't take long to reach the teleportation array.

At this time, four hours had arrived, and Teacher Zheng Jun was asking the students to walk up to the teleportation array in batches and teleport them back to the "Xiaojinghu Branch".

Ximen Feixue, Qingyin, Long Tianao, Fan Qingqing, Zhao Jian and others were anxiously gathering in front of the teleportation array, and everyone breathed a sigh of relief at the same time when they saw Lu Zhan flying back from the air.

Especially the clean sound. At first, she was still anxious, but as soon as she saw Lu Zhan's figure appear, a smile of relief suddenly bloomed on her beautiful jade face.

"Ah, you're finally back!" Long Tianao said in a loud voice: "Fan Qingqing and Zhao Jian have already told me about your affairs in the 'Yin Evil Cave', and we haven't seen you come back just now, we thought you were eaten by the big worms in that cave." ”

Ximen Feixue walked up to Lu Zhan's side, stretched out his hand and patted him on the shoulder, and said softly: "Thank you!"

Lu Zhan nodded at him, and he turned his gaze to Qingyin. The eyes of the two of them met tightly, and at this time, there was no need for words, a single look could say a thousand words.

At this time, Zheng Jun walked up to Lu Zhan and asked, "Classmate Lu Zhan, have you ever seen Gu Dawei?"

"Nope. Lu Zhan replied very dryly. He told this lie with a red face, because he felt that Gu Dawei was innocent. But he also didn't want others to know that Gu Dawei's death was related to him. After all, that guy is also a child of a wealthy family, and if he doesn't get it right, he will cause endless trouble for himself.

At present, the best way is to hide the facts, anyway, there is only one skeleton left in the "Bone Eating Swamp", except for him. No one knows what ever happened in the swamp.

Teacher Zheng Jun sent Lu Zhan and the others back to the "Xiaojinghu Branch" with the teleportation array, while he himself continued to wait in front of the teleportation array until the next day before returning to the academy empty-handed.

That's it. Gu Dawei became the first student to go missing in the Black Iron class.

That night, Lu Zhan gave Qingyin the lotus-shaped crystal stone collected in the "Yin Sha Cave", as he expected, Qingyin had a strong mental stress on the spare, and this material was indeed very suitable for her cave, better than all the quenching materials she had collected herself.

The course is divided into three phases:

The first stage is to teach people how to find quenching materials.

The second stage is to teach people how to temper the "cyclone cannon".

The third stage is to teach people how to control the gas machine to create different gas cannons.

The day after the students collected the quenching materials from the mine, the students were called to a classroom in the South Fourth District.

I saw that there was a small sword pool with a diameter of about one zhang in the classroom, and a turquoise fire was burning in the sword pool.

Feng Baimei and Zheng Jun walked into the classroom, and Feng Baimei announced to the students with a solemn face: "Fellow students, let me tell you an unfortunate news, Gu Dawei unfortunately disappeared during yesterday's activity of collecting quenching materials, and no one knows what happened to him so far......

Lu Zhan sat in the last row of the classroom, at this time he obviously felt that there were a few questioning eyes scanning him, and after following that gaze, he saw Zhou Binglin, Zhu Mingjun and several other male students sitting in the front row all staring at him sideways, as if they knew that Gu Dawei's disappearance was related to him.

Lu Zhan sneered in his heart, sat upright in his seat with an unchanged face, his eyes stared directly at the two teachers on the podium, and turned a blind eye to the puzzled gazes of Zhou Binglin and the others.

Qingyin sat in the front row of Lu Zhan, she turned her face sideways and whispered to him, "I heard Fan Qingqing say that Gu Dawei sold a drawing to you yesterday. ”

"There's such a thing. ”

"Why did he do that?" asked Qingyin, puzzled.

"Who knows, maybe he wants to make a fortune from those drawings. Lu Zhan said a reason, in fact, he now vaguely knew why Gu Dawei wanted to buy the drawings for them, he wanted them to unconsciously walk into the two dangerous places of "Yin Cave" and "Bone Devouring Swamp".

At this time, Feng Baimei on the podium had already finished talking about Gu Dawei, and then she began to teach the students how to quench the "cyclone cannon".

She and Zheng Jun walked to the edge of the sword pool, pointed to the sword pool and said to the students: "Students, the pseudo-spirit soldiers and spirit soldiers in your hands are all tempered through the sword pool. In fact, refining the pseudo-spirit soldier is imitating the quenching cannon, and the material used by the pseudo-spirit soldier is almost the same as the material of the quenching gun.

A good "cyclone cannon" can increase the power of his master's cave mansion by several times or even dozens of times. The 'Cyclone Cannon' used in our cave is a kind of floating cannon, which can move around the cave at will, and at the same time play the role of protecting the cave and attacking, so it is very important to make a good 'cyclone cannon'.

Like refining pseudo-spirit soldiers, quenching the 'Cyclone Cannon' is also done on the Sword Transformation Pool. Some cultivators with a very advanced cultivation level can create a 'cyclone cannon' without passing through the Sword Transformation Pool, but this floating cannon that is not quenched through the Sword Transformation Pool is very poor in durability and has a very short lifespan, and it may be completely destroyed after firing a cyclone cannon beam......

Lu Zhan remembered that when the sword slave first taught him the knowledge of the "Cyclone Cannon", he used a meteorite to create a powerful "Cyclone Cannon", but the cannon was destroyed after only one use, presumably as a result of not being tempered by the Sword Transformation Pool.

In the following time, Feng Baimei and Zheng Jun began to teach the students how to use the different fire in the sword pool to quench the "cyclone cannon", they explained it in detail, and Feng Baimei even used several pieces of quenching cannon materials to personally demonstrate the steps of quenching the "cyclone cannon" on the sword pool.

The materials used in the quenching of the "cyclone cannon" are divided into main materials and auxiliary materials, and the main material only needs one kind, but there can be many kinds of auxiliary materials, so when the trainees enter the mining area to collect quenching materials, the richer the types of materials collected, the better.

There are more than 20 kinds of quenching materials collected by Lu Zhan in the mining area, because the two places he ran are the two most dangerous places in that mining area, and the quenching materials in these two places are very high-grade.

This quenching technique class lasted for fifteen days, until the students basically mastered all the steps and were able to master the different fire conditions in the sword pool for quenching, Feng Baimei began to let the students quench their own "cyclone cannon" in the cave.

Quenching the "Cyclone Cannon" must be carried out on the Sword Pool, but for the vast majority of students who are still at the manifestation level, there is no Sword Pool in their cave at all, and if they want to temper the "Cyclone Cannon", they must do it in the common Sword Pool.

The southern area of the teaching area of the "Xiaojinghu Branch" has an area dedicated to the placement of the sword pool. The sword pond in the southern area is rectangular, the pool is about ten zhang long and more than two zhang wide.

Since quenching is a job that requires a high degree of concentration, it is best to keep the quencher quiet during the quenching process.

So next to the public sword pool, there is a small quenching room, each quenching room has a small sword pool, through a pipe to lead the fire in the outside sword pool to the small quenching room sword pool, students can quench their own "cyclone cannon" in these small quenching rooms, can not only keep relatively quiet, but also enjoy the same sword pool.

Lu Zhan was the only one in the entire academy who had a World Department Cave Mansion, and his sword pool was already there from the moment a small space appeared in his body, so Lu Zhan didn't need to huddle with other students to share the common sword pool.

So, when all the students in the class entered the small quenching room to concentrate on quenching their own "cyclone cannon", Lu Zhan turned his divine thoughts into real images and entered his cave.

He came to the sword pool located at the top of the "Outer Heaven Demon God Temple", and at this time, the big dragon loach had already repaired the hundreds of ichthyosaurs to be obedient. (To be continued.) )