Ban Xia spent an entire day digging a large hole to bury the tiger’s corpse. She wasn’t short on food and had no interest in tasting what the king of beasts might taste like. She just wanted to quickly bury this massive decomposing carcass underground—if she didn’t, every fly in the Qinhuai District would gather for their buzzing convention.
What’s most annoying in summer? First are mosquitoes, and second are flies. Modern people like Bai Yang couldn’t possibly imagine what it meant for “summer mosquitoes to sound like thunder”—a scene they’d only encountered in Shen Fu’s “Childhood Interests” from middle school literature class. But Ban Xia, who often crawled through grass thickets, would sometimes see a dark cloud of mosquitoes ahead and immediately turn to flee with clothes covering her head and face.
By the time she tamped down and leveled the final shovelful of dirt, darkness had fallen. Ban Xia built a small tomb for the Bengal tiger, not far from Building 11. With this tiger eliminated, the Qinhuai District wouldn’t see another Bengal tiger for a long time to come. Bengal tigers required vast territories, and as the saying goes, “one mountain cannot harbor two tigers”—another tiger would at least be in Pukou District, or possibly even in Chuzhou City.
After finishing everything, her arms were so sore she could barely lift them.
“My arms are so sore. I spent all day digging with just an entrenching tool—it was exhausting,” Ban Xia sighed. “BG4MXH, when can you send me an excavator?”
“How am I supposed to send an excavator?” Bai Yang rolled his eyes. “The time capsule isn’t omnipotent. Where would I find a capsule big enough to fit an excavator? The largest time capsules available on the market are only tens of centimeters long. Any bigger and it’s not a time capsule anymore—it’s a safe, OVER.”
“Then make a super-huge safe and put the excavator in it! I believe in you—you can do it!”
“We can’t buy a safe that big; it would need to be custom-made,” Bai Yang said. “That would cost a lot of money, and we don’t have that much, OVER.”
“But you’re saving the world, young man! You could ask that, that… ban…”
“Bank, OVER.”
“Right, bank! Ask the bank for money!” Ban Xia said. “Ask for one million—is that enough? If not, ask for ten million.”
“Are you suggesting I rob a bank? Young lady, I’m just a poor high school student. If I walked into a bank to rob it, the tellers would laugh at me,” Bai Yang said. “What does saving the world matter? Besides, making a safe big enough to drive an excavator into would weigh at least dozens of tons. We’d need a heavy-lift helicopter to transport it. To dig it up, you’d need a heavy-lift helicopter too, so we’d need another safe for the helicopter. Then we’d need an even bigger helicopter to lift that safe—it never ends, OVER.”
“Oh…” The girl crouched on her chair, pouting.
Bai Yang hadn’t yet discovered the limits of the time capsule, but both he and his father knew it certainly wasn’t omnipotent. The Great Filter wasn’t stupid—you might smuggle across a small sampan, but trying to sneak an ocean liner across was like assuming it was blind.
In Bai Yang’s view, size was the first limiting factor for time capsules. They could be enlarged somewhat, but not infinitely. At what point would they become large enough for the Great Filter to detect them?
The Three Laws of Chronological Delivery set the conditions for him. Zhao Bowen had said that as long as they complied with the Three Laws, they could evade the Great Filter. Whatever they wanted to do had to maneuver within those limitations.
“BG4MSR, we’ve been discussing this all day and decided to upgrade your communication methods, OVER.”
There was a pause on the other end.
“Eh? You mean that… that image transmission?”
“That’s a separate system. These two plans are proceeding independently but simultaneously. Building an image transmission link will allow the radio to transmit more and larger data while building a remote control system will let you maintain contact when you’re outside,” Bai Yang explained. “Uncle Wang is heading the remote control system engineering team, and my dad is heading the image transmission system engineering team, OVER.”
“Wow,” the girl marveled. “That’s quite an operation! Who’s on the remote control system engineering team? And who’s on the image transmission system engineering team?”
“The remote control system engineering team has two people total,” Bai Yang answered. “Uncle Wang is the team leader, and I’m the member.”
“What about the image transmission system engineering team?”
“Also two people, OVER.”
“Your dad’s the leader, but who’s the member?”
“Still me, OVER.”
Three people forming two teams—it had to be said that the Future Reversal World-Saving Amateur Radio Emergency Communications Command Center had a long name but short staff, fully embodying the grassroots organizational characteristic of one person working while two people watch.
“Does this mean I’ll be able to see your world?” Ban Xia grew excited. “That’s amazing—2019 Nanjing! 2019! Can you take pictures to show me?”
“Of course, and similarly we’ll need you to show us pictures of 2040 Nanjing, OVER,” Bai Yang replied.
“No problem!” The girl sprang up, slapping the table. “Whatever you want to see, I’ll photograph it… but won’t building these two systems be very difficult?”
Her voice suddenly dropped again.
“Can I do it?”
“We’re still working out the specific plans, but we’ll follow three basic principles. First is simplicity—it must be simple enough for you to operate and complete independently. Any plans that are too complex will be eliminated. Second is stability—all components used must still function normally twenty years later. Third is safety—it can’t interfere with the normal operation of the 725 radio itself,” Bai Yang explained in detail. “You’ll have experts providing technical support throughout the process. Don’t worry, young lady—we’ll handle everything we possibly can for you, OVER.”
The next day.
October 27th was a Sunday.
When Bai Yang got up, Wang Ning and his father were already arguing in the living room. He lazily carried his toothbrush and towel into the bathroom, hearing heated debate outside.
“Have you used it before?”
“Of course I have! I was even the main controller during roll call—frequency 439.675, down 9, sub-tone 88.5. I remember it crystal clear.”
“Is it pure analog or digital/analog?”
“This isn’t right, this is not right. Do you have the schematics? Let’s find some schematics to check!”
“Where the hell do we find schematics for this old relic now?”
“Ask in the group.”
“Who would have this thing?”
“Does TZM have it? Or we could ask STD… that guy usually has everything…”
Bai Yang finished washing up and came out for breakfast, greeting them both.
Old Wang and his father nodded at him, said good afternoon, then went right back to arguing.
“Look, look, I found one—see if this is it…”
“This is nonsense.”
The table had soy milk and shaomai. Mom had already gone out shopping. Bai Yang sat down and felt the cup—the soy milk had cooled somewhat. He took a sip and glanced toward the couch, noticing a foam box by Wang Ning’s feet with a familiar black amateur radio shortwave set on top.
Icom 725.
He blurted out: “725? You got another 725?”
“Bought it second-hand from a colleague,” Wang Ning nodded. “It’s for experiments as a simulation unit.”
Just like in aerospace engineering, where ground control always needed a backup unit identical to the mission unit—if the mission unit in space had problems, people could immediately simulate solutions on the backup unit—Wang Ning had the same idea. Any methods would first be tested on this expendable 725 radio, and once confirmed safe and feasible, would be implemented on BG4MSR’s radio.
Note that at this point, neither Wang Ning nor Bai Zhen realized that Bai Yang and BG4MSR were using the same 725—this key point wouldn’t be discovered until Zhao Bowen returned. Although Old Wang and Old Bai knew BG4MSR also used an Icom 725 radio, the same model as Bai Yang’s, their rich experience as old hams led to a misjudgment. In their eyes, the Icom 725 was truly too classic an amateur radio—just in Nanjing city, there were more 725s than they could count on both hands. It was like the Nokia 1100—you have a Nokia and the person calling you also having a Nokia wasn’t anything strange.
Bai Yang picked up a shaomai and stuffed it in his mouth, asking through the cold dumpling: “What’s next?”
“Next we need to set up a repeater,” Wang Ning said.
“We need to have BG4MSR find an analog repeater first,” Bai Zhen nodded. “Then we can buy one exactly like the model she finds.”
“Can a repeater be sent through the time capsule?” Bai Yang asked.
“Probably very difficult. Pure analog repeater stations are quite large—have you seen one?” Wang Ning gestured with both hands. “It’s as big as a desktop computer case, metal shell, very heavy. No time capsule could fit it.”
“Try custom-making one?”
“You want to find someone to make a time capsule from steel pipe?” Wang Ning considered. “First, it would be hard to find pipe that thick. The seamless steel pipes readily available on the market are a few centimeters to ten-plus centimeters in diameter. To fit a repeater station, you’d need over thirty centimeters diameter, almost as thick as an oil pipeline… you’d need to weld together a capsule that thick, do you know how heavy that would be?”
“How heavy?”
“At least forty kilograms,” Wang Ning answered. “A smooth cylindrical capsule weighing over forty kilos—how would you transport it? You can’t even move it, let alone follow the double-blind principle of burying it without anyone knowing.”
Bai Yang was stumped.
He too sometimes made basic mistakes overlooking practical feasibility.
“We’ll keep the more complex plans as Plan B, backup options,” his father said. “It would be more convenient for her to find a repeater station there than for us to send one because repeaters don’t break easily and nobody wants them.”
“Where are Nanjing’s repeaters?” Bai Yang asked.
His father and Old Wang simultaneously pointed out the window, their gaze passing over the layers of residential buildings.
“Not far, on Purple Mountain.”
“Huh? Purple Mountain?”
Ban Xia was surprised.
“Yes, it’s on Purple Mountain,” Bai Yang said. “Repeater stations are usually placed up high, like on mountains. Nanjing’s 430M repeater is on Purple Mountain, OVER.”
“After twenty years, it hasn’t broken?”
“According to Uncle Wang and my dad, they say repeaters are extremely durable. They’re designed to work without maintenance, and they don’t have batteries, so they don’t break easily,” Bai Yang scratched his head. “Plus these things aren’t valuable and don’t attract attention. You can probably find it, OVER.”
He spread out a crude map in front of him.
The map was drawn by Wang Ning, showing the specific location of the repeater station.
Bai Yang turned it this way and that, finally opening Gaode Maps on his phone—Wang Ning’s map was even less reliable than Gaode Maps.
While looking at the map, he instructed BG4MSR, telling her she needed to find a rod—not a Korean person, but an antenna, specifically the repeater’s antenna.
Ban Xia responded with a series of “mm-hmms” on the other end.
The Future Reversal World-Saving Amateur Radio Emergency Communications Command Center decided to spend the next week upgrading Ban Xia’s communication methods, transforming a fixed amateur radio into a mobile phone with photography capabilities. Once upgraded, Ban Xia would be able to transmit large amounts of image data to this end, allowing Bai Yang and the others to directly face that world of destruction.