"Tabby? Where are you? We're running out of time!" Evan is desperately looking for his sister in the barracks. That fragile metal building was cold, very cold. The vault could be sealed at any moment, and they could be trapped.

"I'm cold, Evie." A faint voice came from under the bunk he had just walked on. Evan knelt down and looked down. His six-year-old sister was wrapped in a blanket.

"Why are you hiding there?" We should already be underground! He scolded and pulled her out. "We've got to run!"

Of course, their running speed is limited to the trotting speed that a small child can do. Evan was only 14 years old and not old enough to run with her.

"Is Mom mad at me?" The little girl asked. "I don't like it there, there are no windows there."

Mom and Dad were worried. I shouldn't have come out to you. ”

Once the door is closed, it should always be closed. The timer is set, and the door will close and won't open again until the blizzard has passed. No one outside the shelter can survive. Rumor has it that the storm will last for months, if not years.

The entrance to the shelter comes into view. Evan could see the massive door slowly begin to close. When he left to look for Tabby, the bastard guard who was laughing at him was arguing with his parents, but the door was still closed.

"Wait! Evan shouted. He picked up the tabby cat and walked faster. He couldn't hold her for long, but it was better than waiting for her. "I found her!" Wait!!!"

The guards pretended not to hear, but his parents saw it and started screaming and pointing at him. When the guard typed out an order on the keyboard, a look of displeasure appeared on his face. The door stopped.

Evan ran as if the door hadn't stopped. He didn't believe the guard wouldn't do it again until he arrived. In fact, just as he slipped in the doorway, gasping and sweating in the cold air, the door began to move on its hinges again.

"Tabby! You're worrying us! Evan's mother said that despite his father's tight hugs for him.

"I'm sorry, Mom," the tabby said tearfully.

"It's okay, everything will be fine," she said, hugging her tightly as the massive iron door slammed shut behind them.

"So we're going to start sending ships out from the outpost?" Sakura asked over the radio. She wasn't in the room. In fact, a few days ago, when Agrippa tried to establish communication with the interstellar probe, she had already left the headquarters area. So far, all attempts to talk to it have gone unnoticed. The probe repeats itself over and over again.

"The time is up," I said. "Is your drone ready to go to the new base?"

"Of course! As soon as you open your mouth, my starter bag will move. We will build four new bases in a week or two. The farthest is 31,809 km and the nearest is 5,212 km. ”

"How long will it take for them to be productive?" I asked, knowing the answer, but wanted to be sure before agreeing. This is the biggest step we've ever taken since our own position was self-sufficient.

"With Ga

Regular material shipments for YMED, initial construction of the plant will be carried out as soon as possible. Since these are mainly military outposts and do not require immediate self-sufficiency, they will be able to accommodate attack drones and produce their own ammunition in about 17 days after landing. They will produce their own drones in 8 months and become self-sufficient in 11 months. ”

"How many bases will start construction in 11 months?"

"All of them."

"Sixty-three people proposed by Agrippa?"

"Yes. The last base will be built within 13 months. ”

"How...", right, self-replication and exponential growth. Sometimes my own human-scale thought processes interfere with basic mathematics. A few weeks ago, we struck 100,000 drones, and this number will double in a month.

"Let's get started now. Do we still have a surplus of basic supplies?"

"We are. The new base will help achieve this, but especially ferronickel and steel, we have tens of thousands of tons in stock. I estimate that the new bases will account for 14% of the remaining capacity, but when they are completed, we will have 118% of the storage capacity. ”

"Is it 118% of current capacity, or 118% of future capacity?"

"The second," she confirmed.

"And what about our military drone production?"

"We build hangars as fast as we fill them. I bought two more today. When the hangars of the first military base are ready, I expect that we will have enough production to fill them on the first day. ”

"Ya?" I called him and got him on the radio.

"Really?"

"How's the communication attempt going?"

"Not good. I think the detector is broken. I've sent a few wasps to find it, but space ...... It's really big. ”

"Ha," Zia said with a smile. "The year is an understatement." I hope you don't mind if I attend this thought session, do you?"

"Not at all," I said, though I did think a little so.

"If you need some help, I can use some of my talents to help you determine the best place to search. We know the trajectory of the probe out of the solar system. If the detector turns direction, it will most likely return in a similar path. Since we know where it exits relative to the Earth, and we know exactly when it leaves, then it's just orbital mechanics. ”

"Oh! If it returns along the same path, we can calculate when and where it returns! Sakura said excitedly.

"Exactly." Zia said enthusiastically. "I'm glad to see that you know how to use your mind and not just build things!"

"I can do so much more with it!" Did I show you my bungee jumping rig in the old entrance tunnel?"

"It's more of a slingshot device," Agrippa said. "I'm still trying to determine if it has a useful training purpose for our Guardian drone."

"You can admit it's funny," Sakura said.

"Wait a minute, is this how your original robot body was damaged?" That's why you switched to Ma before I tested the prototype

k-III?" I asked skeptically.

"Well, I probably calibrated the slingshot wrong, so the bungee pulled me back a little too hard when it reached the finish line...... Newton's laws can be bad sometimes," she says unapologetically.

"It's not that I don't like the progress on this topic, but can we get back to searching?" Agrippa asked.

"Of course. I've built a backup data center for your military drone. Each drone has a real-time backup link to the outpost, so if they are damaged or destroyed, they can be immediately restored to a new one," I said.

"Great! I'm going to start full-fledged combat training for wasps and scorpions. We are well equipped to deal with training incidents. ”

"NI-5 backup," Zia said. "It's smart. I guess they gained tactical experience from training and actual combat, right?"

"Yes." Agrippa said his voice was smug. It's one thing to let a mechanical drone fight for you; It's another thing to have practical thinking, to learn pilots who won't die. Every fight they've ever fought only makes them better in the next fight.

"Well, while that's fun, once I'm done, I'll send you the ideal search pattern. I want to go back to the gravity cabin. I feel like I'm about to break through. ”

With that, the impromptu meeting ended.

"You're so boring," my best friend complained. We have been best friends since elementary school when they moved to our town and his parents joined the church. This is a common complaint; He'll find some ridiculous adventures to drag us back, and I'll protest until he persistently drags me down. But this time, I stood my ground.

"I'm not going to jump off a cliff. I don't care how many times you've done it. ”

It's not really a cliff, it's just that the locals call it a cliff. It is more like a low cantilever, with a boulder and dirt sticking diagonally out of a deep stream. Depending on the creek's water level, it is no more than 20 feet at most, not much higher than the elevated platform of the county swimming pool. I heard about a kid who broke his leg last year when the water was low, but I couldn't believe it.

"You're going to have to try at least once!" It's easy, and you won't get hurt," he pleaded.

"That's what you say about derby roller skating, I just had five minutes of playing and I sprained my ankle and fell on my ass," I pointed out.

He rolled his eyes. "Well, one time I was wrong."

"What about the rope swing you made last summer?" You didn't push me, but you made eye contact with that guy, and I almost planted my face on the shore. ”

"Shhhh As he spoke, he stole around to see if anyone heard. It's a conditioned reflex for him; The two of us were alone on shore, and according to rumors from high school, it wasn't a secret. "Okay, twice."

"Oh, is it? What about when we were kids, you made me climb trees? Aren't you supposed to catch me?" That little adventure resulted in a broken wrist. With this reminder, this time I am even more determined not to follow in his footsteps. I spent too much time planning to escape my mother and her crazy "faith".

"I was too young to know anything," he said, changing the subject. "And you're much heavier than you look."

I was enraged. "You're much thinner than you admit."

"Slut".

"Tramp".

"Man."

He shook his eyebrows. "And some," he said with a laugh. "Well, if you don't go, just wait here."

It was only a moment before I saw him on the top of a cliff. He jumped, but just before he could fall overboard, I heard a "Oh, shit!" I jumped up from the towel I was sitting on, just in time to see him surface and swim towards the shore. Every time he waved his arms, I heard a series of curses. I rushed towards him, and by the time I touched him, I was waist-deep.

"I think my leg was broken," he said, leaning heavily on me.

"The water seems to be a little low." I don't have to say.

"Nonsense, what do you think?" He scolded. ", it hurts. My parents will kill me. ”

"Come on, cliff diver. Let me help you dry your clothes. I'll drive you to the hospital. ”

I didn't say "I told you", but I knew he heard it anyway. Just another ammunition he found for us for the next crazy adventure.

The detector looks in terrible condition. It was originally a 40-meter-long cylinder with an 80-meter-wide solar sail that also shaded the sophisticated electronics. A whole bunch of pipes protrude from the opposite side, a complex but sturdy radiator system that cools the ship. The sail was intended to retract far enough from the Sun, as its cooling gain and slight speed boost weren't worth the micrometeorite damaging it.

But the sail was torn and dragged behind the probe. The radiator tube is bent and several holes can be seen on the probe. I don't know how it's broadcast at all.

"Nothing to look at, is it?" Agrippa said. It took him four months to find it. Saku

A simple cube telescope design was discovered, which was cheap and fast to produce, and hundreds of thousands of units have already been produced. Agrippa used his assault drone to spread them apart while they were training around, and when they lined up, gave us a great tool to search the solar system. NASA may be jealous of our ability to capture and analyze high-fidelity, high-resolution images of the solar system now. Still, it took us two months to get the telescope up and running, and we needed to install another NI-12 to operate it.

"It must have been damaged." Opdeo said that his deep voice was comparable to Agrippa's solemnity. It will orbit Jupiter in six months and will return to Earth orbit in three years. Unfortunately, I can't calculate a good interception trajectory, unless we specifically make a rocket. ”

"What if we aimed directly at the Earth and intercepted it there?" I asked. Three years isn't too long when you have all the time in the world.

"That might be easier," Optio admits. "Now that it's located, I want to continue to expand the telescope array and search the solar system. Someone has led me to believe that we think aliens may have a mother ship. ”

"Say," I said. The survey is starting to feel like a diversion from attention. Or is it a trap? Is it trying to lure us out? In some ways, it does just that. But if we encounter it not when it enters the solar system, but before it reaches Earth, it will be much easier to hide our location. Lots of space and we were very, very small. Alien sensors are weak. I knew that surveillance detectors would make it easier for them to find us. I still can't believe that they don't know where their ship went, and 1035 Ga

YMED is not small and not hard to find. Maybe the aliens are prospectors who just randomly land on asteroids in search of a specific substance? I dispelled that speculation. I've been down this path many times, and the lack of answers only makes me paranoid.

I turned my attention back to my own lab, where Zia occupied her own corner. Zia looked at me and said, "Do you have a few minutes?"

"Of course."

"I figured out the gravity plates," she said, with a big smile on her face.

"That's good news," I said.

"Well, I've finally figured out the spectrometer readings we took." Zia sent me a report related to the strange spectral tests we were doing.

"It's like carbon." I said, I don't understand.

It makes no sense. In the main compartment suspended beneath the fusion reactor, each plate is three meters long, but it accounts for 20% of the weight of the entire alien spacecraft. The plate of leftover pods is much smaller, but it also accounts for 10%. Most of the frames of the ship's central backbone were built to support their enormous weight. Carbon is not that heavy.

"How is this possible?" I asked.

"Well, mostly carbon." She added. "There seems to be a layer of iridium."

"So iridium made it heavier?" The density is much higher than carbon. ”

"Oh, that's the heart of it," Zia said. "The density completely broke the record. The atom is extremely compressed but still retains its physical properties. It's like they're squeezing 100 carbon atoms into the space that a carbon atom should occupy. Iridium is compressed less, though how much exactly, I can't say for sure unless we can cut one open and put it under an electron microscope. But it makes sense, really, because iridium is very dense in the first place. ”

"So how could a species with such primitive materials science be able to create such advanced metals?"

Zia shook his head. "I think the better question is, what happened to the races that created these plates, and how did the aliens get them?"

The meaning of her words struck me. We only encountered one species. But the enemy is intergalactic. It didn't occur to me that this wasn't the first time they had encountered a new alien race, just like us. The fact that their rapidly deploying kinetic bombardment indicates not only that they are violent, but that they have experienced violence, which makes this approach seem plausible. From their point of view, they may have been the heroes who prevented the long war against the "primitive" alien hordes for resources. They will almost certainly not consider themselves genocidal monsters. If we're not the only species that have dealt with them, we might have some allies at some point in the future.

"Okay, but I know you," I said, seeing the smirk on her face. "You know more than you say."

"Well, I haven't figured it out yet. My confusion is amazing, you should plan to give me a Nobel Prize. ”

"There are no Nobel Prizes in mathematics. There are also Fields Medals. ”

"I know, but this thing made me the reincarnation of George Bull."

"Great," I said. "What's that?"

"I applied an electric current to both plates."

"It creates a gravitational field, and yes, we've solved that part." The explosion, in fact, when the pod destroyed the transport and dented the steel floor 10 meters thick.

"Yes, but I figured out the correct current and voltage to control the magnetic field and put a piece of carbon between them." Zia picked up a thin plate of diamond-hard carbon from the table. It is round and looks like a squashed cube.

"So you need gravity plates to create new plates?" I asked. Zia nodded. "So how did the first gravitational plate come about?"

"Ah, now you know the secret! She grinned, clearly interested in the puzzle. "That's why I study mathematics so that we can fully understand the mechanics."

"So what practical applications can we do with it?"

"Well, we can use it as a local weapon to create a shattered gravity between two points, or hell, even as a molecular knife to cut out layers of atomic thickness. Maybe it's a field where objects can be lifted or moved. Once we figure out the math, the sky is the limit. So far, all I can say is that the aliens have a precisely calibrated gravitational field aimed at two points above the spacecraft. Therefore, the ship always "leans" in the direction they wish to go. Want to speed up? Increase the power of the magnetic field. Want to stay where you are and hover over the Pacific Ocean? Balance the gravitational field so that it is completely opposite to the Earth's gravitational pull. ”

"Well, so we can balance, let's say, hover the drone with a small plate, tilt the plate to make it move in the direction you want?"

"We can," she admitted. "Theoretically, we use something like this to move anything. Or even... Damn, that's what they did. These bastards. ”

"Do what?" But then I realized, and I raised my hand to stop her answer, and that's when I suddenly realized. This is how they move asteroids. All that is needed is a large enough array of gravity plates and a sufficiently powerful fusion drive. Now we know what to do.