"You mean those walls outside are beast-proof?" Scarab took over the conversation.

"It's not certain yet. The outer wall is tall and sturdy, and in order to build such a wall, one must have one of the following two conditions: first, there were many people involved in the construction of the wall. The second is that the construction of the city wall lasted for a long time. We first need to find out how many people lived here in the past, and then we can determine their motives for building the walls. Zuo Dengfeng said.

After a night's rest, everyone's physical strength and spirit have recovered, and the cave immediately began to be lively, and everyone hung a pot to boil water and cook on the stove.

Although the outside world has been infected by bacteria, the remaining food is not only sealed canned food, but also many vacuum-packed vegetables, and the breakfast is very rich, with wine and vegetables, meat and rice.

"Check the food after eating and see how many days it lasts?" Zuo Dengfeng took Jia Zhen and handed over the food and said to everyone.

Everyone nodded and agreed, after breakfast, they counted their equipment and supplies, because Zuo Dengfeng found a large amount of ammunition before, there were still a lot of bullets and grenades left, and the twenty kilograms of food carried by each person were almost not consumed, and the dry food carried by Datou and Wan Xiaotang was relatively small, only about ten catties, and Zuo Dengfeng had been carrying hundreds of catties of dry food in the wooden box, according to the calculation of one catty of drinking water and one catty of food per person per day, the supplies carried by everyone could last here for twenty days.

Zuo Dengfeng informed everyone of the results of the calculation, and everyone showed a relieved look when they heard this.

"Don't be too optimistic, the nearest supply delivery site is also thousands of miles away, not to mention that we may not be able to find it, we must prepare for the worst, at least five days' worth of food." Zuo Dengfeng said.

"There is enough time, maybe it won't take half a month." Big Heads are still optimistic.

Zuo Dengfeng nodded slightly when he heard this, stood up and pushed the door and walked out, it was still windy and snowy outside, to be exact, it was just wind, the snowflakes were all snow blown up by the strong wind, and the visibility was limited, such an environment was not suitable for searching.

Zuo Dengfeng stayed outside the cave for a while, and opened simple thatched huts on the left and right sides of the cave, and then pulled the door back.

"There are thatched huts outside, men on the left and women on the right." Zuo Dengfeng sat back on the wooden bed.

As soon as these words came out, everyone rushed out, Wan Xiaotang and Jia Zhen also walked out one after another, and when they passed by Zuo Dengfeng's bed, they all cast a grateful look at him, thanking him for his thoughtfulness and avoiding the embarrassment of the two.

Due to the strong wind outside, everyone took a break in the cave, Datou and Scarab and others were making all kinds of speculations, Zuo Dengfeng did not participate, although he was good at analysis but did not want to do meaningless analysis, the current clues are insufficient, the so-called speculation of Datou and Scarab is actually speculation.

"Check the guns, check the straps of the backpack, the laces, the buttons of the pockets, don't miss any details you can think of." Zuo Dengfeng saw that everyone was idle, so he reminded him.

When everyone saw Zuo Dengfeng speak, they immediately checked the details again.

"Qiu Muyu, according to the breath of the animals outside, determine a relatively safe route in advance, I mean walking on the city wall." Zuo Dengfeng commanded at the head, and everyone's gossip and speculation seemed to him to be very purposeless and purely time-consuming.

"Okay." The big head nodded in agreement.

"Ma Jingui, after you go out, you are responsible for protecting Wan Xiaotang, walking at the back of the team, if there is danger, we will deal with it." Zuo Dengfeng gave an order to the scarab.

"Zuo Zhenren, how can this work?" Seeing that Zuo Dengfeng had arranged the safest task for him, Scarab couldn't help but feel slightly ashamed.

"Your task is to protect the rear and the pilot, and to make sure there is no danger behind. Wan Xiaotang must be closely protected, she is not a soldier, she is the weakest of us here. Zuo Dengfeng explained.

"I'm holding everyone back." Wan Xiaotang said in a low voice, she had flown civil aviation before, and her physical strength really couldn't keep up in this treacherous environment.

"Don't say that, when we get to a crowded area on the way back, we still have to find a plane to fly back, you are still very useful." Zuo Dengfeng smiled and spoke.

"Zuo Zhenren, otherwise, with this as a base, they will stay behind, let's go out to search, so that we can speed up." The big head thought for a long time and said.

Zuo Dengfeng frowned when he heard the words and looked at the big head, the big head was hairy by him, but he didn't know why Zuo Dengfeng looked at him like this, and in the end, Wan Xiaotang and the others also looked at him in amazement, and the big head was even hairier.

"I'm sorry, I'm sorry, I forgot, I didn't mean to." Raising his head and patting his head, he ignored the most basic problem, that is, if everyone left the protection range of Zuo Dengfeng, they would immediately suffer from the virus.

"I don't blame you, you also think about everyone's safety." Zuo Dengfeng shook his head and said. The reason why Datou ignores the existence of the virus is because the environment here is very different from the outside world, but this environment and the surrounding things make Zuo Dengfeng very comfortable, which makes him feel like he has returned to the days when he was looking for the earth branch everywhere.

At noon, the gale gradually weakened, but the outside world was still not suitable for human activities, Zuo Dengfeng did not rush to action, and did not call everyone on the road until the gale completely stopped in the afternoon.

At this time, everyone had completely recovered their strength and marched forward on the city wall. Nine meters is equivalent to a three-story building, and people without aura cultivation feel terrified when they walk on it. As he walked along, he turned his head to observe the mountain, and found that there were weeds and shrubs on the mountain in the snowless area, but there were no tall trees here.

"Did you notice, there are no big trees here." Zuo Dengfeng said to the big head.

"Noticed, how could this be?" The big head said suspiciously.

"The tree must have been cut down." Zuo Dengfeng said.

"Possibly." The big head echoed.

Zuo Dengfeng immediately frowned and stopped, muttered for a moment and turned to the right peak, removing a layer of snow from the mountain peak with a mountain move, and looked down at the withered plants under the ice and snow.

"Qiu Muyu, come here." Zuo Dengfeng waved his hand at the big head, and the big head swept over when he heard the sound, and Zuo Dengfeng stretched out his hand and pointed to a huge tree root under the ice that had been cut down for the big head to watch.

"It's more than two meters in diameter, and the cutting tool should be something like a saw." The big head looked up for a moment and said.

"What is this?" Zuo Dengfeng stretched out his hand and pointed to a few branches growing from the edge of the stump, the branches were the thickness of a shovel handle, and they had dried up at this time.

"What happened to the new branches that came out of the trees after they were cut down?" The big head asked suspiciously.

"When did the Japs release the virus?" Zuo Dengfeng asked rhetorically.

"Two and a half years ago, Zuo Zhenren, if you have something to say, just say it." Datou smiled bitterly and said, before he met Zuo Dengfeng, both Datou himself and the people around him appreciated his intelligence, but since he met Zuo Dengfeng, Datou found that he had suddenly become a fool.

"Modern people don't go to the North Pole with a saw to cut down trees, and you can conclude that this giant tree was cut down many years ago, and after the tree was cut down, new branches were pulled out of the stump, what do you think caused the death of these branches?" Zuo Dengfeng frowned and asked.

"Naturally, it's the virus emitted by the explosion of a nuclear bomb!" The big head replied immediately.

"Nonsense, the age when the giant tree was cut down was at least thousands of years ago, and the new branches on the stump should have been in the years after the giant tree was cut down, why didn't the branches grow in thousands of years?" Zuo Dengfeng is still a rhetorical question, in fact, he already has the answer in his heart, but he wants to induce the big head to learn to think, after being frozen for ninety years, he finds that modern people are very lazy to use their brains, and a slightly more difficult question makes them worried.

"You mean that not long after the giant tree was cut down, the plants here stopped growing?" The big head finally got his senses.

"Yes, the plants here have nothing to do with viruses at all, because the plants here have withered thousands of years ago, what do you think is the cause of the plants withering?" Zuo Dengfeng nodded and asked again.

"It's cold, maybe the Arctic gets very cold for a while." The big head didn't dare to talk nonsense, and only after thinking carefully did he open his mouth.

"No, it's already cold here, and plants can't grow at such a low temperature, and the reason why plants here were able to grow before was because of the radiation from meteorites, and within the radiation range, the temperature is a few degrees lower, and the plants can still grow." Zuo Dengfeng frowned and shook his head.

"You mean to say that the plants here have withered because the radiation from the meteorite has disappeared?!" The big head stared in amazement.

"Yes." Zuo Dengfeng smiled bitterly and nodded.

The big head was instantly shocked into a cold sweat when he heard this, and the disappearance of the radiation indicated that the meteorite was not here, if this was the case, everyone's trip to the North Pole would be in vain.

Zuo Dengfeng immediately turned around and swept back to the city wall, and regardless of whether the meteorite had an accident or not, the search must continue, no matter how accurate the speculation is, it is not as accurate as the facts.

After a while, the big head also came back with a sad face, he was in a bad mood for two reasons, one was that the search for meteorites had become a variable, and the other was that he knew that Zuo Dengfeng's real age was only two or three years older than him, Zuo Dengfeng's angle of analyzing the problem was strange and tricky, and he didn't follow the usual path at all, but he could always get the right answer, which made the big head who followed the rules extremely awkward, both admired and angry.

After five miles, there was a ramp leading diagonally to the mountain again, and there was a cave similar to the previous one under the mountain, but when he arrived here, Datou did not stop, but continued to walk, he was afraid that Zuo Dengfeng would ask him questions again.

"Zuo Zhenren, do you want to go in and have a look?" Jia Zhen raised her gun and pointed at the cave.

"No, according to pi, there will be more than 300 miles of city walls here, and here is five miles away from where we rest, which means that there may be more than 60 similar military stations near the city wall, and there were more than 300 soldiers stationed in those years, so we don't need to go to see them one by one." Zuo Dengfeng said casually.

"Zuo Zhenren, you always think so much, are your brains tired?" The big head stopped and turned to look back.

"Soon I won't have to be so tired, let's go, the city gate should be in front of ......"