Humans Are Selfish
There was only one thing I had to do.
I'd wasted a fair stretch of time — moping around after being left on my own, then going off to hunt down the cultists' hideout. All sorts of reasons. But in the end, I still had to build a radio repeater.
"This is 303. Requesting a trade. Reply if you copy."
Ever since I'd parted ways with Harin, whenever I had a spare moment I'd go back through her textbooks and notebooks, turning over the memories of those days again and again. Every kind of curse had been echoing off the walls of my room every night, but I couldn't bring myself to give up.
Yeah.
I couldn't deny it. Being apart from her this long, I missed her. I'd agonized over it the whole time. Wrestled with it. And in the end, it all led to the same thought: even someone like me wanted her back.
Maybe it was selfish. But humans are selfish animals by nature. So I was going to make the selfish choice, same as I always did.
"I want to trade cigarettes and alcohol for eight radios, and I also want to use a soldering iron. I'm going to build radio repeaters."
Even assuming one repeater every four or five kilometers, I'd need four of them to safely cover the more than twenty kilometers to Cheongdam-dong. Meaning on top of the ones I already had, I needed to build four new repeaters.
The answer didn't come back right away. These days, radios probably weren't exactly sitting around in piles. Harin and I had already taken five, and four more had gone into the repeaters we'd built for the airport group. If they dipped into their stock any further they might come up short, so they were probably talking it over.
And then—
"Understood."
The answer came after a little while. So that was it — no more radio trades after this one.
"Copy."
I stood up immediately. No point sitting around staring at the wall and sulking. It was time to work.
A backpack stuffed with cigarettes, and precious metals. In the apocalypse there was no such thing as a set price; everything floated with the going rate, and eight radios plus the use of a soldering iron went for exactly that. Well. Supply had dried up a long time ago, but demand had kept right on going thanks to a certain trading partner named me. Nothing to be done about it. I still had plenty of cigarettes left, so it was fine. As long as I didn't finally crack and start smoking them myself.
Which meant…
Corporal Cha. Please. Give me strength.
"Hoo… you dumbass. Don't you go smoking this shit."
Ahh!! Cigarettes you smoke alone are the best, Marine-nim!
Alright, that's enough. Get back inside already.
Anyway. I headed into the airport.
Park Jinseok came running out in his socks to greet me.
"Aigoo! If it isn't our cigarette quartermaster!"
"That title is extremely unpleasant."
I'd thought this last time too — I was starting to understand why Harin had hated being called the tuna-mayo quartermaster.
"Heh heh, but if it weren't for you, 303, we'd all be sitting here with the shakes from withdrawal. You're our savior, man. Our savior."
"Yeah, yeah. I get it. Just take the cigarettes."
I held the backpack out to him, and he clutched it to his chest with trembling hands, like I'd just handed him a fistful of luminous jewels. At this point, this guy's nicotine addiction was getting seriously out of hand.
"Khh! God, I'm grateful every time! I could drop to my knees and lick your feet!"
"Ah, come on."
Park Jinseok counted the cigarettes, then nodded.
"Good. Count checks out. I already put the eight radios on the workbench."
"Thanks."
"But you can make it even without that girl around? Last time I figured she just didn't come with you, but… she's not dead, is she?"
Harin was alive and well. If anyone was going to die, it'd be me first. Nobody dies living in that insane bunker in Cheongdam-dong.
"There are circumstances. So I'm going to try making it on my own."
"Hmm, I don't know the details, but you should apologize already. They say it's usually the guy's fault."
No.
"…I didn't do anything wrong."
"That's what they all say. And then you end up dying a lonely old bachelor like me. That's life for you."
…
What the fuck was with the completely random life advice.
Besides, I really hadn't done anything wrong. If I had to dredge something up, it was just that I'd been rejected by the people in Cheongdam-dong for being an orphan brat with a hundred million won in debt. But a deranged collaboration attack by the mother and father I'd never even seen and that fucking bitch Jeon Seon-ju was not my fault.
I cast my mind back.
Last time, Harin had gathered materials to build a radio repeater. The airport electronics store. Fragments of memory that had been scattered and flickering came together, little by little, as I arrived at the same place.
I can do this.
I'd spent days turning it over, studying.
A 3.5mm audio cable. A 3.5mm plug. A 5V relay module. A 2N2222 transistor. A 1kΩ resistor. A 1N4148 diode. And wire. I couldn't even count how many nights I'd spent howling at the ceiling trying to drag those parts out of my memory.
The audio cable was a pair of earphones. The relay module, I was sure, she'd pulled out of a washing machine. The transistor she'd ripped off the circuit board on the back of a TV. The 1kΩ resistor and the 1N4148 diode had both come off electronics circuit boards, and the wire from a warehouse stacked with leftover stock.
I followed the faint trail of those memories and retraced Harin's steps one by one. I couldn't do it as perfectly as she had, but I gathered the parts with clumsy, fumbling hands, copying her as best I could.
I can do this. I can make it on my own. I'd had four months of excellent teaching. I ought to be able to do this.
One way or another, I got all the materials together. It had taken me twice as long as Harin, who'd stripped the machines down and pocketed the components like she'd been born doing it — but the parts I'd collected were the same as last time.
I let out a breath.
It's fine. I can do this.
I'd brought a sample from home, knowing it would come to this. All I had to do was set the radio repeater Harin had made down beside me, study the connections slowly and carefully, and copy them exactly.
"From now on, this one's the receiver, and this one's the transmitter."
Chun-sik and Sam-sik. Recalling the explanation she'd given me, I set two radios down and connected each one's earphone jack and microphone jack with the 3.5mm audio cable.
"VOX is probably built into the radio… is this the menu?"
I still had no idea what that was, but I followed the memory and did exactly what she'd done — opened the transmitter's menu and switched a setting called VOX to ON. Sensitivity at level three.
"Ah, ah."
The damn radio had no obligation to follow my memories, and just like last time, it didn't work. Which meant what I had to do, in the end, was build the circuit.
I studied the finished unit slowly, trying to recall the order.
The receiver's earphone output was soldered to a 1kΩ resistor and the transistor's middle leg. The transistor's left leg was soldered to the positive side of the relay coil, and the negative side of the relay coil was connected to the positive of the 5V power supply. The remaining right leg of the transistor was soldered to the ground wire.
Staring at all those tiny things, my eyes started to blur. I rubbed them and picked up the soldering iron. The hand holding it was shaking.
"See? It's easier than you think. You can do this too, oppa."
Bullshit.
"Bad word. Minus ten points."
The same. I just had to connect everything the same way, following along.
I took a deep breath. In and out, slow, over and over, until the tremor in my hands settled.
I can do this.
The same way Harin had gone from being a complete disaster at shooting to actually being good at it under my teaching — I, a total amateur at anything resembling engineering, could get good at it under hers.
I let out a breath, and soldered.
Receiver earphone output to the 1kΩ resistor and the transistor's middle leg. Transistor's left leg to the relay coil's positive. Relay coil's negative to the 5V supply's positive. Transistor's right leg to the ground wire. It was a little clumsier and sloppier than what Harin had done, maybe, but I copied it without getting anything wrong.
Next was the relay circuit.
"This is the device that'll automatically trigger the PTT."
I don't know.
"Dummy."
I still didn't know. I still didn't understand. There was a decent chance I would go to my grave without understanding it.
"So what."
Even so, I was chasing the memory, following the path her hands had taken. Two contacts on the relay switch. One I connected with a red wire to the transmitter's PTT terminal, the other with a black wire to the ground line marked GND.
A 3.5mm plug — in other words, the cut-off end of an earphone cord. I slotted the severed plug into the transmitter's microphone jack, held the PTT button down, and touched the multimeter to it.
"That's continuity test mode."
And what's that supposed to mean.
"Just pat my head, would you."
I wanted to do nothing but pat her head, the way I had then. But to do that, I had to bring her back. And building this was the first step.
A beep.
Same as last time.
Next were the green wire and the black wire. Green was the PTT signal line… Chun-sik. Black was the ground… Sam-sik. I couldn't remember the proper names.
Anyway. I connected the relay contact's red wire to the green one, and the contact's black wire to the black one.
Unlike the Harin in my memory, even with the work almost finished, the hand on the soldering iron was still clumsy and unsure. If she'd been watching from beside me, she probably would have been giggling.
And then—
"It's done."
I was sure that was what Harin had said, once she'd gotten this far. Unlike her, I didn't bother tidying up the tangled mess of connections, but I found myself matching the frequencies and, the way she had, making a sound into it.
"Ah, ah."
The repeater caught my voice. The transmitter's PTT kicked in on its own and sent it out.
…
It worked.
I'd actually built it by myself. It looked clumsy and crude, but I'd done it. Alone. Without her.
And so I was staring blankly at the thing I'd made when a voice came from behind me.
"Whoa, what? 303, you made this by yourself? For real?"
…
"303? Hey, cigarette quartermaster?"
…
"Wait, hold on. No. Are you crying? Hey, hey, why are you crying. You just gotta say you're sorry first, that's all, come on… Want a cigarette?"
Fuck.
I hadn't meant for this at all, but a few tears had come out.