“Hey hey, let me have a drink of water first! Even when interrogating suspects at the police station, they give them water to drink, right?” Faced with the questioning from everyone around him, Old Zhao remained calm as he picked up the water glass from the coffee table. He took a big gulp, then let out a long sigh and slapped his thigh forcefully. “Damn, I’m exhausted. Finally got it done though. It wasn’t for nothing that I racked my brains. You have no idea how many places I had to run to, how many people I had to find, how many cold shoulders I got, how many times I had to kowtow, how many connections I had to pull!”

“We don’t care about all that. I just want to know what exactly you did,” Wang Ning said.

“Tell us. Leniency for those who confess, severity for those who resist!” Bai Zhen said with mock solemnity.

“What kind of attitude is that…” Zhao Bowen rolled his eyes. “You should all be thanking me, you know? If I hadn’t pushed this through with everything I had, who knows how long this would have taken? The people at the Eighth Academy must hate me now – I made them work overtime for a whole week… Come on, applaud! Everyone give me applause! If the applause isn’t enthusiastic enough, I won’t tell you anything.”

Wang Ning, Bai Zhen, and Bai Yang had no choice but to start clapping.

“More enthusiastic! More enthusiastic!”

Everyone else clapped until their hands were red, but Zhao Bowen still wasn’t satisfied. Old Bai got angry: “You dick, are you ever going to be done?”

“Hey hey, mind your manners! How can you use such foul language in front of children?” Zhao Bowen fell back onto the sofa and said lazily, “Actually, I only did one thing – set off fireworks for that little girl.”

“Go on.”

“Yang Yang, do you remember the Three Laws of Time Delay that we discussed before?” Zhao Bowen’s gaze fell on Bai Yang, who started slightly, then nodded.

“I remember.”

“The Three Laws of Time Delay, when you get down to it, are fundamentally about weakening purposefulness, right? If you greatly weaken the purposefulness, you can trick the Great Filter.” Zhao Bowen explained, “But that explanation is too vague – it has reference value but no practical use. So after I went back that day, I started thinking about this problem. I wanted to find a mathematical method to describe this mechanism. Later I visited some old friends and discussed this problem with them. Finally, we came up with a model, a formula. The model is very complex – Shanghai Jiaotong University’s supercomputer helped build it. In the model, there are three most important parameters: one is correlation, one is temporal distance, and one is spatial distance. If we draw it as a simple coordinate system…”

Zhao Bowen sat up straight and took a pen from the coffee table, drawing a rectangular coordinate system on a piece of scratch paper. The horizontal axis was L, representing spatial distance, the vertical axis was T, representing temporal distance, and the distance from the origin represented correlation.

“We simulated and constructed many, many scenarios, using convolutional neural networks to learn. The method was simple and crude, but very effective – AI’s judgment speed is much faster than the human brain.”

Zhao Bowen started plotting points on the coordinate system, then straightened the draft paper to show everyone around him. He had uniformly plotted dense clusters of small points in the first quadrant of the coordinate system.

“Each point is a scene, an event, an experiment. They are discrete, with no relationship to each other.”

“We input all of them into the model for calculation and performed the first screening. The criterion for this screening was whether time delay could pass through the Great Filter. The result of the first screening looked like this.”

Zhao Bowen drew a diagonal line in the coordinate system, from a high point on the vertical axis toward a far point on the horizontal axis.

“Everything below this line failed – their correlation with the origin was too strong, the purposefulness too strong, and they would be caught by the filter. Only the parts above this line, far enough from the origin, could escape the filter.”

“The farther an event is from the origin, the lower its correlation with the origin, and the lower the correlation, the lower the purposefulness.” Zhao Bowen explained, “This matches our human intuition, right? The farther something is from you, the lower the possibility of it having any connection with you. A supernova exploding at the edge of the galaxy would have no relationship whatsoever with those present here right now.”

“So is the optimal solution that points diagonal to the origin?” Bai Yang asked. “That point is the farthest in both space and time, so its purposefulness would be the weakest.”

“Wrong. Next, we need to perform a second screening.”

Zhao Bowen waved his hand and drew another line on the coordinate system, very close to and parallel to the first line.

“The target of this screening is whether the time delay delivery can be retrieved after being sent. Note the second line – the parts above this line, although they can escape the Great Filter, will be lost in the vast world due to their correlation being too weak, and can never be found again.” Zhao Bowen explained while shading the area between the two lines with his pen. “The final result is a very, very narrow interval between these two straight lines. Below the lower limit, it will be discovered by the filter, above the upper limit it will be lost and scattered. Mathematically, these are two thresholds: 1.256748931 and 1.256748932. They only differ at the ninth decimal place. Only between them is there the highest probability of success.”

Bai Yang nodded as if half-understanding.

“Didn’t get it,” said Bai Zhen.

“That’s okay, I didn’t get it either,” said Zhao Bowen. “This is the result given by AI. Normally, the human brain can’t understand a computer’s thought process. We can only input and adjust parameters – as for what comes out, it’s all up to their mood.”

“In this very narrow interval, we got three events.” Old Zhao poked the shaded band on the paper with his pen tip. “Only one event was relatively close to our situation. In this experiment, the AI set up a scenario like this: a time interval of twenty years, and a spatial distance of 70 million kilometers.”

“Is this the prototype for your plan?” Wang Ning asked.

“Yes, I immediately went looking for ways to fly 70 million kilometers away, so my first stop was the Eighth Academy.” Zhao Bowen nodded. “During this time, the intelligence Yang Yang passed to us was very helpful, giving us a fuzzy understanding and estimate of Black Moon’s influence. The Eighth Academy discussed it for a long time – no one could be certain what kind of impact the Black Moon would have on spacecraft in Earth orbit. We could only prepare for the worst-case scenario, assuming that Black Moon’s arrival would destroy all spacecraft in low Earth orbit, geosynchronous orbit, and even lunar orbit… so we made a crazy plan.”

Zhao Bowen slapped his pen down on the coffee table with a “bang!”

“Let it fly 400 million kilometers away,” Old Zhao declared grandly. “To Mars!”

Old Bai, Old Wang, and Bai Yang were all stunned.

“That’s… that’s incredible,” said Wang Ning.

“But time was urgent – we didn’t have enough time to prepare another Long March 5 rocket, so we had to make do with what was available. We targeted a rocket that was about to perform a commercial launch – a Long March 6 carrying a telemetry satellite for a domestic company, called Ningxia-1.” Zhao Bowen said, “We intercepted it.”

“Inter… intercepted it?”

“We requisitioned this rocket on an emergency basis and replaced the payload with our own. The Fifth Academy must have been furious.” Zhao Bowen said, “The payload design was very simple, even crude – it wouldn’t carry out any scientific observation work. Its only mission was one spectacular death: it would take twenty years to visit Mars, then precisely at midnight on November 15, 2040, re-enter Earth’s atmosphere and crash gloriously in the skies above Nanjing.”

“The Long March 6’s thrust was too weak, so we equipped it with the most powerful electric propulsion currently available. It can slowly change orbit toward Mars on its own – we’re not in a hurry anyway. It has a full ten years to fly to Mars, and another ten years to fly back. It carries an extremely precise clock that started counting from launch until precisely midnight on November 15 twenty years later when it enters the atmosphere.” Zhao Bowen continued, “Setting off an unprecedented fireworks show for that girl.”

“How did you manage the multicolored meteors?” Bai Yang asked.

“Simple, just like fireworks – flame color reactions.” Zhao Bowen grinned. “Speaking of this, we racked our brains over it, trying to figure out how to make it look best when it bloomed. After studying it for a long time, we decided to use hollow metal spheres of different materials. When the satellite breaks up on atmospheric entry, it releases the metal spheres which create flame color reactions through high-speed friction with the atmosphere – those are the meteors. The metal spheres are sealed with inert combustion agents inside. When these decompose at high temperatures, the internal pressure of the spheres rapidly increases. Once the outer shell burns through, they burst open, becoming fireworks.”

“So you’re saying you spent all this time and resources just for a fireworks show?” Wang Ning asked.

“Yes, am I awesome or what?” Zhao Bowen asked.

“Awesome!” the three replied in unison.

“Fortunately, satellite modular design is very mature now, so our ideas quickly took shape. That satellite launched yesterday afternoon from the Taiyuan Satellite Launch Center. The public announcement still called it Ningxia-1, since this matter is classified.” Zhao Bowen said, “To prevent human interference, it will shut down all external communication channels after entering orbit. As we speak, it should be on its long journey to Mars.”

When he finished, he sighed.

“For the next twenty years, across millions of kilometers, it can only rely on itself.”

This was truly a massive project.

As Zhao Bowen put it, he had moved the Earth.

Bai Yang could hardly imagine how Zhao Bowen had completed such complex work in just half a month – what mad dog-like speed that was.

Zhao Bowen very modestly said that people perform best under pressure – you don’t know how fast they can work until you push them. He had only done a tiny bit of work, played a small role, such as transforming into a vicious dog chasing after them, and the fact that the academy’s senior leader happened to be his distant cousin.

The next day.

Bai Yang was finally going to start testing the image transmission system. He had carefully selected more than a dozen photos covering various scenic spots in Nanjing and had even especially taken a group photo with He Leqin and Yan Zhihan – though young master He and Brother Yan looked quite reluctant.

Bai Yang excitedly returned home with his phone but found even more people at his house than yesterday. If this was what Uncle Zhao meant by an army of thousands, he had certainly delivered.

Zhao Bowen stood in the living room with people coming and going around him – some wearing black jackets, some in camouflage uniforms, some in white protective suits with goggles and masks, and some walking around clicking Geiger counters. Bai Yang was stunned – at first glance he thought a murder had occurred in his home.

He saw these people packing up all the materials and equipment, including his old Icom 725 amateur radio as if they were moving house – but moving company staff certainly wouldn’t be as efficient as them. People in white protective suits methodically unplugged and bundled all the cables from the radio, carefully placed it in a foam box, then sealed and locked the box.

Dad and Uncle Wang stood to the side with their arms folded, watching these people busily working, their expressions somewhat complex.

“Uncle… Uncle Zhao?”

Bai Yang called out from the doorway.

“Hm? Yang Yang?” Zhao Bowen turned his head. “You’re back?”

“What… what’s going on?” Bai Yang asked.

“Taking everything away,” replied a middle-aged man in black beside Zhao Bowen. “Your work is finished. More professional people will take over from here.”

Bai Yang opened his mouth but didn’t know what to say. He could only grip his phone tightly as a man in black carrying a cardboard box stood before him. They faced off for a moment before Bai Yang stepped aside, letting them file out one after another.

They practically dug three feet deep, packing up and taking away everything that might be useful, not missing a single scrap of paper.

“Uncle Zhao, I…” Bai Yang gathered his courage to speak – he wanted to say he still had an unfulfilled promise.

“What is it, Yang Yang?” Zhao Bowen turned his head.

Others turned their heads with him, those cold, stern gazes falling on Bai Yang, making his scalp tighten.

“…No… nothing.”

Your work is finished.

More professional people will take over from here.

This is right, Bai Yang told himself in his heart. This is how it should be. Isn’t this the result he had always hoped and prayed for?

The strangers quickly left. Zhao Bowen was the last to leave. As he was walking out the door, he turned and gave Bai Yang’s shoulder a firm pat.

“Yang Yang, you did very well.”

Bai Yang silently nodded.

Zhao Bowen left, taking everything with him.

Bai Yang stared blankly at the bright, spacious living room. The messy draft papers, materials, cables, and radio had all vanished. Even the floor had become clean and shiny – those people had helped clean the house before leaving.

Dad and Old Wang stood opposite him. Uncle Wang spread his hands somewhat helplessly.

This is right.

Bai Yang told himself.

This is right.

But you’ll never see her again.

You didn’t even get to say goodbye.

He gritted his teeth and ran after them, racing down the stairs.

“Uncle Zhao—! Uncle Zhao—!”

Zhao Bowen hadn’t gone far. He had just opened the car door but hadn’t gotten in yet, one foot on the doorstep. “What is it, Yang Yang?”

Bai Yang, who had chased out of the building, stopped, panting. “Uncle Zhao… can you help me with something?”

“Tell me.”

“I promised her I would let her see this world.” Bai Yang said. “So… can you help me send the photos to her? I’ll send them to you, and you help me transmit them to her.”

Zhao Bowen was stunned for a moment, then smiled. “Sure, piece of cake. Leave it to me.”

He got in the car and closed the door. The car drove away.

Bai Yang stood alone downstairs. He had rushed out without putting on a coat, and the cold wind was biting. November 15, 2019 – it was as if the shadow of doomsday had suddenly been blown away by the wind, along with a certain girl who would forever disappear from his life. The parting came so suddenly, not even giving you a chance to say goodbye.