Ban Xia woke up early the next day, humming songs while packing her things, and bouncing around the room.

She was in a good mood.

For breakfast, she had cabbage and lotus seed porridge paired with cold marinated shredded venison. The salt-cured smoked venison was a bit tough, so it had to be shredded into thin strips – when eaten with the lotus seed and wild vegetable porridge, it was quite fragrant.

Today she was going out! Going to complete a historic meeting! The first reunion of the remaining survivors after the destruction of human civilization.

If humanity continued, today would surely be a day recorded in history books – September 8th, the date human civilization began anew. If religions still existed in the future, then today would be like the seventh day of Genesis in the Bible, like when Moses parted the Red Sea in Exodus. In the New Bible hundreds of years later, it would be written: When Ban Xia turned on her radio, Maxwell used electromagnetic waves to make the survivors known to each other in one night, awakening the city, humanity reborn.

“You who descended from the sky, landing on my horse’s back.”

Ban Xia hummed while carrying her bag, spreading all her necessary equipment across the living room floor, filling the entire space.

She checked them one by one.

There were lighters and fire starters – the fire starter was a magnesium rod and half a saw blade. To light a fire, you’d use the saw blade to scrape magnesium onto dry grass or paper to ignite it. This type of fire starter was simple in structure and waterproof.

“Like jade your appearance, eyes clear as spring water, a slight smile making my heart burn hot.”

This time Ban Xia packed double the amount of dried food, each portion wrapped in plastic. If the number of people here increased later, the pressure on food supplies would grow too.

Fortunately, Nanjing never lacked food.

“You who never looked back, spreading your pair of wings!”

“Searching for direction, direction lies ahead.”

The girl hummed as she went down the stairs step by step, opening the door to 703 downstairs.

This apartment was empty, and all furniture was removed. As Ban Xia opened the door with a creak, a small furry pointed face peeked out from the bedroom.

“Good morning, Old Master Huang.” Ban Xia greeted it, “Did I disturb your sleep?”

Old Master Huang was used to her, curling up at the bedroom doorway, scratching an itch with its front paws, squinting as it yawned.

This yellow weasel had lived here for many years. When Ban Xia first noticed it, Old Master Huang was already a resident here. It lived in 703, and when 703 was later requisitioned by Ban Xia and her teacher as the power distribution room, they didn’t drive it away. Instead, they often brought it food, and this weasel lived quite comfortably in its later years.

Ban Xia closed the door behind her, and stepped into the living room, carefully avoiding the white PVC pipes on the floor. All miscellaneous items had been cleared from this apartment, leaving only a huge metal rack and a rusty silver cabinet standing against the wall, with the rack holding an entire wall of car batteries.

Forty in total.

Forty car batteries, with dense black cables extending from them, then branching into dozens of white PVC pipes, running out through the living room’s floor-to-ceiling windows – quite a spectacular sight.

Back then, her teacher had led her in collecting all the working car batteries they could find and bringing them here. Since then, all their electricity has relied on these forty car batteries. One battery’s voltage was 12 volts; connecting forty batteries in series created a 500-volt high-voltage power source. This massive battery bank connected to the silver cabinet beside the rack – an EPS (Emergency Power Supply system) that they’d found in the hospital of nearby Nanjing Agricultural University. It was essentially an inverter that could convert 500 volts to 220 volts.

The EPS ran lines up the stairwell, with 220-volt AC power going up to 804 above, providing electricity for Ban Xia’s daily life.

The battery bank had three sets of lines in total, two outputs, and one input.

Besides the line outputting to the EPS, another output line bypassed the EPS cabinet, running directly out the floor-to-ceiling window, down the exterior wall, and connecting to the high-voltage fence.

The high-voltage fence was just a barrier about a person-height, using insulated wooden posts as supports. Every two or three meters stood a wooden pole as thick as a bowl, with metal wires running along the wooden framework to encircle the entire Building 11 of Zhongqin Yuan.

The metal wires were stripped outdoor telephone cables – twisted pairs of three copper wires and four steel wires, with the steel providing strength and the copper ensuring conductivity, making them the perfect material for an electric fence.

The wooden framework held six levels of wire from top to bottom, with ten centimeters between each level, all insulated and not touching. The first, third, and fifth were positive, while the second, fourth, and sixth were negative – under normal circumstances, they remained separated, peaceful, and non-interfering. But if an intruder touched the fence, connecting adjacent positive and negative circuits, the 500-volt charge would strike dead any unwelcome guest.

Unlike what many might imagine, the high-voltage fence consumed no electricity in its normal connected state, because the positive and negative poles of this circuit were open. As long as nothing crashed into it, it could stand there for a year without using much power.

What about rain?

Ban Xia had asked.

Wouldn’t rain conduct electricity?

No, her teacher had patted her head, as long as the voltage doesn’t exceed 1000 volts, we don’t need to worry about rainwater.

The solar panels were responsible for charging the battery bank – Ban Xia and her teacher had removed them from street lights. After humans disappeared, the solar street lights continued working, lighting up punctually after dark, shining lonely in this dead, empty city like the lingering souls of human civilization.

The solar panels were all mounted on the exterior balcony walls, not laid flat on the roof to prevent bird droppings. Each solar panel produced about a dozen volts, perfectly matching one panel to one battery – extremely simple and crude, but design simplicity came at the cost of practical effort, and they’d worked their hands to cramping connecting all these tangled cables.

After connecting the cables, the room looked like a spider’s web. For easier organization, Ban Xia and her teacher categorized and bundled all the cables, threading them through white PVC pipes to prevent rats from chewing them.

Rats loved to chew on electrical wires.

This was why Ban Xia and her teacher had kept Old Master Huang in 703 – with Old Master Huang around, rats wouldn’t dare to be so rampant.

Every two days Ban Xia would come down to check the power supply. She stood before the battery bank for a long while, then crouched down to pull out the gasoline generator from under the rack, wiping off its dust.

“Old Master Huang, oh Old Master Huang, what do you think about letting other people stay here if they come?”

Ban Xia turned to ask.

Old Master Huang lay on the floor, its small black button eyes staring at her, front paws covering its moist nose, gaze innocent.

“Alright, alright, we won’t drive you away,” the girl chuckled, “Besides, people can’t live here anyway. Let’s have them stay in the apartment across the way.”

Old Master Huang tilted its head, unclear whether it understood or not.

Bai Yang came out of his room yawning, while his mother seized the chance to go in and mop the floor.

She only went in after Bai Yang came out, to avoid seeing anything she shouldn’t.

His father sat at the table browsing headlines, with the TV on – CCTV13 was playing News Live, the anchor’s voice serving as the room’s background music:

“According to reports, our country will officially launch the Voice Seeking Project next year. This is our country’s first active initiative to search for potentially habitable exoplanets and even extraterrestrial civilizations. The Voice Seeking Project may inject new vitality into exoplanet exploration activities…”

Bai Yang plopped down in a chair, took a sip of water, and pointed at the image on TV: “If only we had an antenna that big, wouldn’t it be amazing to use it for radio communication?”

His father glanced up, “That’s FAST, a radio telescope.”

“Can it transmit?”

“It can only receive, not transmit,” his father said. “That big dish can hear aliens whispering – using it for amateur radio would be like using a cannon to kill a mosquito. You were up late last night playing with the radio again, weren’t you?”

Bai Yang glanced at his mother, then nodded secretly.

“How’d it go?”

“There was one person, that illegal operator I mentioned to you before – I made contact with her again. She’s not illegal,” Bai Yang answered. “BG4MSR.”

“BG4MSR?” His father frowned.

“Her call sign.”

His father tried hard to remember, then shook his head, “Never heard that call sign. Could she have gotten certified recently… but CRAC hasn’t held any exams lately, has it? Ah, I’m not sure, I uninstalled HamSpectrum anyway.”

“I uninstalled HamSpectrum too.”

“Why?”

“Couldn’t open it anymore,” Bai Yang said. “Never mind that – Dad, give me some advice. BG4MSR wants to meet up, today at six in the evening, at the intersection of Mu Xu Yuan Street and Zhongshan Men Road. What should I do?”

Looking back now, Bai Yang didn’t know why he’d agreed so readily – he’d agreed clean and neat, but then spent the whole night tossing and turning, unable to sleep.

This must be what pure-hearted young boys agonize over.

That’s what Bai Yang thought.

“Oh?” His father was quite calm about it. “She’s from Nanjing too?”

Bai Yang nodded.

“That’s good then, just go – ham radio operators often meet up offline, and you can exchange technical knowledge,” his father was unperturbed. “Do you know how your mother and I met?”

“How did you meet?” Bai Yang was startled – could it be a match made by radio waves? Met through ham radio?

“Through a matchmaker.”

Bai Yang: …

“What I mean is, you don’t have to be like me,” his father explained. “Back then I was in the army, didn’t have other options, had no choice but to use a matchmaker. If I hadn’t been forced into using a matchmaker, how could I have married someone as… as…”

“As what?” His mother’s head poked out of the bedroom like a ghost, the room temperature suddenly dropping five degrees.

“…as perfect and excellent as your mother?” his father said.

His mother snorted coldly and withdrew.

Father and son both breathed sighs of relief.

“Yang!” his mother called from the bedroom, “I don’t object to you meeting anyone – if you want to go, you can go, but you have to finish all the math worksheets that were handed out today! Teacher Liu emphasized in the group chat that they’ll be reviewed tomorrow!”

Bai Yang sighed – before six o’clock this afternoon arrived, he still had mountains of homework to climb that could crush someone to death.

Could there be anything more difficult in the world?