Tonight, a small insect emerged from its hard pupal shell, its soft wings becoming less fragile in the wind, and it looked forward to the first drizzle of spring, and the croaking of frogs in the pond, and the two teenagers under an umbrella in its eyes. It waits, it waits.

The sting began.

On a certain day, a certain month, the end of the fantasy of many people chatting has arrived.

The first human to realize that something was wrong was a scavenger living in a slum in the tropics of the continent. In the morning, he rubbed his eyes and squeezed out of the deepest part as usual. The clothes on his body were already dirty, and he didn't know what the original color was, and in some places it had even been torn into strips of cloth. For him, the weather never made him feel cold, so such clothes were enough to get by. As he poked his head out and squinted at the eastern horizon, a chill passed through his chest, and he felt something stained in his hair, and then his eyebrows became heavier, his fingers stiffened, and his whole body began to tremble, and he didn't know what was wrong. Before the next gust of wind blew, his whole body was already purple from the cold, and his eyes were white and miserable where the sun had not risen on the horizon as usual.

The northern hemisphere has just passed the vernal equinox, and the cold time has not yet passed. So, by the time people really feel something is wrong, the temperature has dropped to minus 10 degrees. For the first two or three days, there was a little more clouds in the sky as far as the eye could see, and although there was no sun, people were used to continuous cloudy days. People who wake up every day live in the fantasy of the cold spring, adding clothes to themselves day after day, and no one overly monitors the daily temperature changes, let alone pays attention to the fluctuating changes in the intensity of solar radiation on the surface. When people found that the increase in clothing could no longer suppress the trembling of their bodies, everyone began to breathe cold in the direction of the horizon, hoping that the warm golden yellow would replace the miserable white and illuminate the earth.

The temperature is minus 23°C

Small-scale ice ages occur every 2-40,000 years, and large-scale ice ages occur every 100,000 years. Scientists believe that the irregularity of the Earth's orbit changes how much energy it absorbs, causing the Earth to cool suddenly. But studies have shown that irregularities in the Earth's orbit account for only 1% of the Earth's absorption of solar energy. Even so, the Sun's luminosity at near the galactic center is minimal, which still causes the blue planet to cool. Are nature and the universe controlled by God? Until now, it was not known whether God had finally decided to teach the atheist scientists some lessons, if they existed. The Ice Age has finally arrived.

Before the temperature gradually approached minus 35 °C, the Joint Command Center for the Continuation of Human Civilization and Disaster Prevention was re-established, and the previously stagnant underground transfer operation was officially launched. About a century ago, a scientist who was called a great man before the present situation took shape had predicted this situation. The scientist took up the post of chief designer of the underground transfer operation when the joint command center was first established. At the time, underground evacuation operations were only a pre-planned activity for future disaster defense. This project has been going on for a century, and it has been a long and tortuous process. For a century, the construction of the dungeon was not very rapid, so it did not cause popular discontent or excessive government policy pressure. However, at the end of the century, faced with an economic crisis that swept the world, it was decided to halt the construction of dungeons, abolish the Joint Command, and concentrate on dealing with the enemy in front of them. Through the media and other forms of propaganda, people believe that there is no point in engaging in such useless construction at a time when there is not enough to eat. The scientist who led the defense plan was called a god and a madman before his death.

The structure of the underground city is divided into two floors, which also have light sources and other artificial ecosystems for humans and organisms to live in, and the structure of the two floors is completely separated, and the geothermal elevator in the edge area is mainly used to connect the ground and the passage of the first and second floors. Because the two layers of the ecosystem are separate, they can accommodate a much larger number of humans and organisms. In fact, at the beginning of the design, the "mad" scientist had already predicted that when the disaster came, the moment the human beings realized the disaster had come and began to move, the human population should have been rapidly reduced by the harsh environmental impact, so the number of people who eventually moved to the dungeon was just below the threshold that the dungeon ecosystem could bear.

Temperatures have reached minus 60 degrees Celsius, and global cooling has begun to lead to mass extinctions. After the barbaric age, the Neolithic Age, the Great Industrial Age, and the technological age, human beings finally couldn't stand the harsh natural environment, and on the way to the underground city passage, the fallen and frozen corpses were worshipping the body of nature, their desperate eyes and mouths that opened their faces because of fear were frozen into perfect works of art.

The dungeon is arranged in such a way that the elderly and young people under the age of 25 live on the second basement floor, and the young people aged 18-25 are mainly used as the future force for the revival of science and technology and the second force to protect and guard the elderly and children in the current situation. The basement floor is mainly inhabited by people over 25 years old who have a strong labor ability, and are the first force with the main resistance and defense ability. In addition to traveling back and forth between the ground and underground to find supplies during the ice age, one of their purposes was defense. And the object of this defense is not the so-called alien invaders, but the defense against human civil strife.

In such a distribution situation, the separation of children from their parents is inevitable. Chen Yuan, Qiangzi, and Lao Qin took the old people of our grandparents' generation to live on the second floor of the dungeon, while our parents had to live on the first floor of the dungeon to do the main work. Before entering the dungeon, you will have to go through the same security system as at the airport. The main thing is to separate the humans who enter the dungeon from the lethal equipment, and the definition of lethal equipment also includes a series of daggers such as long daggers for civilians. Chen Yuan could understand the center's idea of making this request, in this ice age of large-scale human transfer and the need to share limited resources for a long time, even a small fruit dagger can become a powerful equipment to kill the other party in the era of resource plunder.

Chen Yuan and Qiangzi, Lao Qin moved from the southeast coastal area to the first passage in the northwest inland, and we went through a strict "security check" before entering the dungeon. In the passage into the dungeon, Qiangzi took the backpack back, he secretly put a short dagger in Chen Yuan's pocket, Chen Yuan was surprised, we came here from the southeast and went through more than a dozen "security checks", how could Qiangzi come here with three short daggers and not be found.