(The second update is released today and will return to normal tomorrow)

This is a strange world, a strange world composed of ice and snow.

This is a cave with only a hundred thousand square meters. The wind blowing from the entrance of the cave circles in the cave with warm and humid air. The moisture in the air turns into flying snowflakes under the action of the low temperature in the cave. The wind that loses its temperature and humidity brings the cold cold and snow on the ground, and blows out from the exit of the cave.

"It's so cold." The thin Vivian rubbed her face red from the cold and complained in a low voice: "I had known that I would have come with a tent, and it could block the wind if I had a tent."

"It's useless to have a tent here." Lina sat cross-legged on her backpack carelessly, and raised her eyes from the book: "The ice surface is too hard, and it's hard to get the tent up. Speaking of which, you are the only one of the four of us who shouldn't be afraid of the coldest. The only place where you are cold is your face, but my whole body will be cold. If you want to complain, I should complain."

"You are wrapped in such thick clothes, so it won't be cold." Vivian waved his little hand and strengthened his tone: "As for your face, you are so thick-skinned, of course you won't feel cold."

"Vivian." Catherine glared at Vivian and said with a slight reprimand: "I said that it is only you. You are here, unless necessary, you are not allowed to leave the cover of the crystal. You can quickly withdraw your hand."

"Why is it me the only one?" Vivian protested dissatisfiedly, but when he saw Catherine's stern eyes, he retracted his hand and said, "Okay okay, I understand."

Rachel looked at the interaction of the three girls with curiosity, a little curious about the ban Katherine issued to Vivian alone, and wanted to ask why, but she wanted to speak but stopped.

"It's nothing." Although Vivian didn't look at Rachel, she seemed to know her doubts: "My hands don't feel cold. My sister is afraid that I don't know whether I feel frostbite on my hands, so she set this rule for me. In fact, it's not that exaggerating. My sister is just worried. Okay, I won't say it anymore, don't glare at me."

Catherine shook her head and smiled bitterly, lowered her head and used the metal rod originally used as the crystal energy lamp holder to penetrate into the ice cave several meters deep, stirring the water at the entrance to prevent the water from freezing again: "Pennis has been going down for more than two hours, so he should be coming up? After all, the time limit for underwater breathing agents is only two hours."

"Sister, don't worry." Lina waved her hand indifferently: "According to him, there are no monsters under the water, he will not be in danger."

"Forget it, I won't wait here." Vivian said and stood up: "I'll go to sleep in my sleeping bag for a while. Even in the past seven or eight days, I can't rest with peace of mind, and my head will hurt to death. It's rare that it's safe here, so I'll go and rest for a while."

Catherine waved her hand: "You can take a break between us and take care of you. By the way, you have something on your face to block the wind."

"I know~~" Vivian said in a long voice: "My long-winded sister."

Catherine snorted angrily, and the eyes of Vivian looking at Vivian's back were full of pity. Although Vivian turned his back to Catherine, she knew exactly what Catherine was thinking. She said leisurely: "Sister, don't do this. I'm very good. I'm so good, not forced at all, don't feel uncomfortable for me."

"You are smart." Catherine complained in a low voice, and suddenly felt the resonance crystal in her pocket vibrate, and quickly put away the metal pole: "Pennis is coming up."

Before he finished speaking, a sound of water was heard. Panis fish jumped three or four meters high from the water, and landed lightly next to the crystal energy stove lit in the center of the girls. Heavy hand over the water on his face, and reached out to take the activated fire-attribute crystal handed over by Lina and placed it in front of his face, slowly eased the numbness on his face, and said, "Are you all okay, where is Vivian?"

"Vivian needs to rest for a while, she can hear it, but she is too lazy to speak when she is resting, so she doesn't have to pay attention to her." Catherine said, "You are not frozen below, right?"

Panis felt that his face had warmed up, so he picked up the boiling water that had been heating up on the stove and enjoyed the warmth of the water vapor: "It's actually okay, the water is warmer than this one."

"Have you found the entrance?" Hearing Panis say nothing, Catherine was relieved and asked about the situation underwater.

"No, I'm fooled." Panis looked dissatisfied.

"What? The information is wrong?" Catherine frowned, a little worried.

"It's not a matter of intelligence." Panis shook his head and explained: "It is said that there is a small lake in the center of this cave, but it turns out that it is true. But who knows that the entire cave is actually a lake. The range of the lake contains the entire cave, and it is at least thirty meters deep. In this way, the range of exploration is too large. Even if you simply look at each place, it will take a long time."

"So I said I'll go down to help you explore together." Catherine was very dissatisfied with how she could do nothing.

Penis picked up another bottle of underwater breathing potion and put it in the pocket of the waterproof leather jacket, and refused again: "Forget it, you are not an explorer, so it's useless to go down. And there are not many underwater breathing potions, so save some use."

"You want to go down again?" Katherine was a little worried when she saw Pennis's actions: "Do you want to take a rest?"

"No need, I have some ideas. I need to go down and verify it. If you are lucky, you should find the entrance next time you come up." Panis walked to the hole on the ice and poked the frozen water surface with a metal rod for a few minutes without stirring: "You are careful on it yourself, it is not absolutely safe here."

"We will be careful, you yourself... well, you have already gone down." Seeing the water splashing in the ice cave, Catherine pursed her lips helplessly, and glared at Lina who was smirking: "Stop laughing, you have many ideas, come here and discuss it, you can help me think of a solution."

"What kind of way?" Lina sat down near Catherine, her behavior was quite rough, glanced at the ice cave, and said suddenly: "You mean..."

"Yes, that's what it means." Catherine smiled apologetically at Rachel, and leaned over to Lina and whispered. Rachel moved a few steps away from the two people who were quietly communicating.

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"Temperature, temperature." Panis got into the water and destroyed four fire-attribute crystals everywhere in his body through the waterproof leather jacket, so that the whole body could soak in cold water without any temperature protection. It was not until the body completely adapted to the temperature underwater that it began to slowly swim. The thoughts in his mind quickly turned: "The institute was built near this place, and it must be used to absorb the energy of the ice element here to provide energy. Then, the temperature near the institute would be very slightly higher than that in other places. Then, as long as you feel the slight changes in temperature and follow the changes, you can always find it."

Panis, who made up his mind, focused most of his attention on his skin, and carefully sensed the changes in the surrounding temperature while tentatively moving downstream.

"There is indeed a difference." Panis said to himself: "The more you go here, the more obvious it becomes. It is estimated that the temperature can be raised to the point where anyone can find the difference. It seems that this is the one."

Thoughts circling in my mind, Panis swam faster and faster, and soon swam to the edge of the lake and slowly searched along the rock wall.

"Sure enough." As he approached the bottom of the lake, Panis slapped his hands, looked at a dark hole on the rock wall with a little joy, and thought to himself: "If nothing unexpected happens, it's here. But for the sake of security, I'd better go in and take a look first."

After swam into the cave tentatively, Panis found that this was an oblique upward passage with a gentle slope. According to this calculation, the end of the passage should be several thousand meters away. After swimming hundreds of meters along the slope, artificial traces could be seen around the slope. Then swim forward a few hundred meters. The surrounding rock walls have been replaced by artificial stones.

Swimming to the end of the ramp, Panis discovered that this was a shaft more than ten meters deep. One side of the shaft was equipped with a metal ladder for people to climb, but the metal ladder that had not been maintained for hundreds of years had been rusted and could not be used.

A soft light could be seen on the shaft. Panis, who had already confirmed that he had found the target, turned around and re-entered the water and returned quickly. After swimming for a while, Panis suddenly felt a tremor of the resonance crystal under the waterproof leather jacket.

"This is a sign of the situation on it." Panis felt a stern, but slowed down his swimming speed. The closer he approached, the slower the hole, so that his swimming would not make any sound. When he arrived at the hole, he found that the hanging metal pole was still slowly stirring the water surface to prevent the ice from condensed again.

Seeing this scene, Panis knew that Catherine still had enough, and said that the situation was not yet very urgent, so he reached out to tap the resonance crystal and sent a signal to it. It was not until he saw the metal pole retracting that Panis floated out quietly. As soon as he came out of the water, Panis discovered an abnormality. The crystal energy lamp on it had actually turned off and the ice surface was pitch black.

Panis tapped the resonance crystal again in confusion, but found that the crystal quickly responded to the vibration, and at the same time heard Catherine's low voice sound from above: "Come up."
Chapter completed!