The Moon is an intimate and mysterious celestial body for the Earth, which is about a quarter the diameter of the Earth and is the only moon of the Earth, the largest in volume and mass relative to the planets it orbits. One side of it is always facing the earth, as if it is watching the earth all the time, while its little-known back side hides the military airport of the moon back base. When human beings walked into the center of the earth and opened the inner world of the Earth Ark, they discovered that the guardian of the Earth Ark since ancient times was the moon, and it turned out that the entire interior of the moon was hollowed out, and there was a self-sufficient moon base made of superalloy inside. This explains that no matter how big the crater on the moon is, the deepest depth is 6 kilometers, because there is an extremely hard superalloy shell beneath the surface of the moon, and under the protection of this indestructible superalloy shell, the base on the back of the moon is an important military fortress to guard the earth's ark. It has a self-sufficient subsistence system such as oxygen supply purification, water recycling, food production and waste decomposition and reuse, and hundreds of warships left down from ancient times are on call at the military airport of the moon base on the far side of the moon, which is the main entrance and exit of the moon base. Hidden under the surface of the moon, there are thousands of high-energy pulse cannons that can automatically track moving objects and aim and shoot, guarding the Earth Ark on the front line, deterring the alien race, so that the aliens know that they can find "Yuan Shui" on the Earth and do not dare to cross the thunder pool by half a step, and they are more willing and honest to buy "Yuan Shui" full of spiritual power from the Earth Ark every year. The moon base is theoretically built at the same time when the Earth Ark was built, and its central operating system and daily operation director are the brain "Moon Shadow", which is a derivative system of the Earth Ark's brain "Silver Moon", which can be simply understood as a subsystem under the jurisdiction of the brain "Silver Moon", one large and one small, one light and one dark, one main inside and one outside the main outside. The "Silver Moon" of the Earth Ark Brain and the "Moon Shadow" of the Brain of the Moon Base will be connected every 500 years for system updates and information synchronization, and after information sharing and synchronization, the two brains will be indistinguishable from you and me, but before the synchronization, the two brains are independent individuals and will have their own unique thoughts and autonomous actions. Since the last synchronization, there will be 100 years before the "Silver Moon" and "Moon Shadow" will be synchronized and information shared. Therefore, the current intelligent brain "Moon Shadow" of the moon base is an individual with independent thinking, and he now has a forward-looking plan for the future development of the Earth Ark, because it has a shocking discovery about the rise and fall of the solar system in outer space, and this discovery prompts him to take action, even if it violates the instructions of the intelligent brain "Silver Moon", he will not hesitate.

Before the Inner Earth was opened to humans, the people of Atlantis were stationed at the base on the back of the moon, and Atlantis was the chosen human race who was tasked with guarding the Earth Ark and the base on the back of the moon, and held the key to unlocking the promised land in the center of the earth. When humans opened and settled in the Inner Earth, the Atlantis returned to the underwater world of the Ark of Earth to live in seclusion. The operation authority of the moon back base has also returned from the Atlantis clan to the hands of surface humans, and after learning to drive and repair the star warships left over from ancient times to the Atlantis clan, human beings will use the moon back base as a base in space, constantly explore the solar system, and communicate with alien races, and the main alien races are 3: Virvir giants, zergs and robots, they are all from galaxies outside the solar system, for example, the Virgilant is from Andromeda, and the Zerg is from Sagittarius, Robots, on the other hand, are silent about where they came from. These alien races have one thing in common, that is, they rely on "Yuan Shui" to maintain their life and self-awareness, they are all chasing the source of water and coming to the solar system, according to the Virgen family, the galaxies outside the solar system only leave ordinary water resources, that is, empty water sources, these water have very little spiritual power content, and human beings have always lived in a place where "Yuan Shui" is abundant, and regard the precious "Yuan Shui" as an inexhaustible resource, so they cannot understand and feel the pain of water shortage. When the alien race tracked the water resources of the "Yuan Shui" to the solar system where the Earth is located, they found the "Silver Moon" and "Moon Shadow" of the brain "Silver Moon" and "Moon Shadow" that silently guarded human beings in the Earth Ark and the Moon Back Base. The alien races gradually came to a consensus that without understanding the mysterious process of the creation of the "Yuan Shui" of the ball, everyone would only observe human beings, and would not attack or invade the earth, because occupying the earth is undoubtedly an unwise action to kill chickens and take eggs.

Pain! Li Xinjian suddenly woke up from the nightmare, only to see himself sitting on the ground next to the bed with a quilt, it turned out that he had just fallen from the bed to the ground, he didn't know where he was for a while, his head was blank, and he was in a daze for a while, before he remembered that he was now in the living dormitory of the moon back base. Yes! Li Xinjian thought that the appearance of crown fungi and dead wood forests started with the "Ark Pioneers" in the Moon Back Base, so he should be able to find relevant clues and the whereabouts of his parents when he went to the Moon Back Base. Half a year ago, he entered the moon back base as a trainee astronaut candidate, and was assigned to the detachment under the command of his father's former partner Captain An Ran, and his sister Li Xinying needed to enter the training camp for half a year because she was accepted as a heart master apprentice, and when she was separated from her sister Li Xinying, Li Xinjian said wistfully: "Sister, I will take the first step and wait for you at the moon back base, let's find my parents together and wash away my father's suspicion of spreading crown fungus."

Li Xinying also relentlessly admonished: "Be careful, you are my dearest relative, the whereabouts of your parents can be traced slowly, but don't be too risky, you have to wait until I finish the training camp and the faction is left behind at the moon back base before we act together!" Li Xinjian nodded, watched his sister Li Xinying walk away with tears, and then went to the moon base alone and embarked on an unknown journey. Before leaving Eden, Li Xinjian asked to see the lord of Limad, and asked him to provide a replica of the Crown Fungal Ink Pen found in their home. The city lord Limad agreed, and the day before Li Xinjian set off for the moon base, he received a 3D printed ink pen replica.

Captain An Ran rang the doorbell at the door of Li Xinjian's dormitory, and asked loudly, "It's time for Xiao Jian to get up!" We have breakfast together, and then it's time for your first spacecraft internship. You have been here at the Moon Base for nearly a year, and in the past you would only conduct various flight training in the base's simulated cockpit, but today you finally have the opportunity to practice piloting an astronaut in the space airspace near the Moon Base. Were you too excited to sleep last night, and woke up late this morning?"

Li Xinjian got up from the ground next to the bed, put on a coat haphazardly, opened the door and invited Captain An Ran in, and said, "Uncle An Ran, please wait a while, wait for me to freshen up quickly, and we will go to the public dining room for breakfast together."

In the public dining room, Li Xinjian and Captain An Ran dined together, Li Xinjian asked: "Uncle An Ran, did I perform well in the internship flight today, and after this assessment, I can become a real trainee astronaut and be responsible for assisting in the operation of the interstellar transport aircraft?"

Captain Enron replied: "Yes, today's internship training will be conducted by you in the position of the chief engineer, fully responsible for piloting the spacecraft, and I will sit in your deputy position, monitoring your performance throughout the process, and the intelligent system will record your physical and mental condition and driving skills during the internship. If you can successfully complete the internship assessment today, congratulations, you have truly become a member of the Moon Shadow Base, and as an astronaut of the Moon Shadow Base has a special mission and mission!"

Li Xinjian sat in the main control room of the spacecraft, and Captain An Ran sat beside him, only to see Li Xinjian skillfully driving the spacecraft into the orbit over the moon, flying in the direction of Mars, and finally entering the ice crystal group at the tail of a comet. The training was chosen today because there is a comet in outer space approaching the earth, and the comet's tail carries a large number of ice and snow crystals, and Li Xinjian's mission is to pass through the tail of the comet flying through the ice crystals. I saw him driving the spacecraft safely, dodging left and right to dodge the scattered ice crystals flying in space, the average diameter of the ice crystals is one kilometer in size, if the spacecraft unfortunately hits it, it will definitely be crushed. When Li Xinjian tried his best to dodge the oncoming ice crystals, there was a small ice crystal flying from the rear, and An Ran shouted: "Look at the radar, this ice crystal is flying at such a tricky angle, it is very likely to hit our spacecraft, you should deviate from the course a little to reduce the degree of damage!"

Li Xinjian didn't say a word, concentrated, locked the trajectory of the ice crystals in the radar while driving, counted down one, two, and three in his heart, and pressed the launch button of the laser beam without hesitation. An Ran shouted loudly.."It's really worthy of Li Huasheng's son, this time you did a good job, I dare to guarantee that you will be able to ......" Captain An Ran didn't have time to finish his appreciative speech, and saw a piece of ice crystal with a diameter of two kilometers flying rapidly in front of the right side of the radar.

Back to the Moon Back Base, An Ran and Li Xinjian went to the main control room to get the reception of the Zhi Brain "Moon Shadow", all the active personnel of the Moon Back Base need to be recognized by the Zhi Brain "Moon Shadow", they looked at the humanoid face shaped by memory metal, the mouth of the human face opened and closed, and said cold words without emotional fluctuations, this is the external shape and image of the Zhi Brain "Moon Shadow". The "Moon Shadow" highly praised Li Xinjian's performance and granted him the official status of a trainee astronaut at the Moon Back Base, after which Li Xinjian could participate in the space mission of the Moon Back Aircraft Base.

In the aisle of the base, Li Xinjian and Captain An Ran stepped on Lin Feng, the captain of another astronaut team, and Captain Lin Feng said to An Ran: "Dude, after you returned to the Ark of Earth with Brother Watson last year, the organic pickled cucumbers you brought back from American City in the Northern Hemisphere were really delicious, do you still have stock? I'm greedy! I heard that the Watson brothers and their family traveled in the biosphere of the Ark of Earth for 3 months, and I remember that you also visited relatives in American City at the same time, and also stayed for 3 months, did you contact the Watson brothers? His life after retirement must have been very free."

Captain Enron said, "Yes! The Watson brothers are having a great time living in the Ark of Earth! This is his son, Li Xinjian, who has just passed the examination to become a full-fledged trainee astronaut, and will become an excellent guardian of the earth in the future, just like his father Watson."

Li Xinjian heard the conversation between the two, his heart moved, and a chaotic idea emerged, but after thinking about it carefully, he couldn't find the point, and he was thinking about the American City in the Northern Hemisphere! American City in the Northern Hemisphere! American City in the Northern Hemisphere! In a flash of inspiration, he remembered that Detective Rhine had said that his father, Li Huasheng, and his mother, Liu Mei, had received a communication from the American city in the northern hemisphere, and disappeared after leaving the city the next day. Enron should have remained in American City at the time. Li Xinjian telepathically connected with his sister Li Xinying, and he asked his sister to check with the city lord Limad to check whether Captain Enron stayed in his hometown of American City a few days before and after Li Huasheng and Liu Mei's disappearance in March last year, and whether he had any contact with other personnel from the moon back base. The seeds of suspicion had been planted, and Li Xinjian thought about how to investigate it carefully.