The Glint Only I Could See
Wooooong—
Inside the production line, a mechanical drone whined loud enough to ring in my ears.
I am an equipment engineer. More precisely, a semiconductor equipment engineer. My job is to repair and improve the tools on the line, and even now I was rushing from one end of it to the other to do exactly that.
"Lee Seokhyeon. You planning to move anytime today?"
A voice thick with irritation called my name. My senior. He'd been unnecessarily unkind to a new hire who hadn't even been here a month.
I pulled two wrenches from the toolbox I'd brought and held them out.
"Here you are, sir."
"Yeah."
He answered curtly and took them. He was wedged under a cramped tool, swapping out an air valve, and I bent at the waist to watch him work whether my back liked it or not. If I didn't steal the technique with my eyes, he wasn't going to teach me a single thing.
"What, you here to sightsee? You finish your dailies?"
Dailies. The checks that had to be done every single day. And of course I'd finished them.
"Yes. I checked everything on the way in."
"...You talking back to me? Go check again. You never know what might've gone wrong."
"Yes, sir. Understood."
At times like this, agreeing was the smart play. I got to my feet and made a circuit of the line. There was nothing special about a daily. You went tool by tool and looked for anything out of the ordinary.
Wooooong—!
The machines screamed. Every one of them was so old that the noise seemed worse for the years on it.
How can a tool be older than I am?
A few weeks ago, I had joined one of the world's leading semiconductor giants. Dazzling production lines, state-of-the-art equipment, and me growing up somewhere in the middle of it all—that was what I'd pictured. Reality had other plans. I'd been assigned to Line 1, the first line ever brought online. And not even to the memory division, the company's cash cow and its core business, but to the foundry division, which took orders from other companies and ran their product.
Luck like mine is hard to come by.
You'd have to look a long time to find someone in my position. It was a major corporation, so quitting wasn't an option either.
Flash—
Just then, a glint of light skimmed across one of the tools.
That again.
A light that had started appearing out of nowhere sometime after I joined. I'd even asked my senior whether he could see it, and all I'd gotten back was a sharp edge.
You messing with me right now? Must be nice, having that kind of free time.
Come to think of it, I saw it over there earlier, too.
Under the tool my senior had crammed himself into. Not the air valve he was replacing now—the one beside it had been glittering. It seemed like only I could see it, and I had no idea what it meant. While I turned that over, I finished the second round of dailies and headed back to where he was.
WN-1. When I got there, he was on his feet, dusting off his hands.
"All finished, sir?"
"Oh, we're all finished, are we? You want a report while you're at it?"
Why is this man so difficult?
"No, sir. Thank you for the hard work."
"Right. Clean up. Crawling under a tool like that, my whole body's killing me. Ugh."
With practiced ease, he tossed the leftover tidying onto me. Well. This much was well within a new hire's duties. I gathered the removed air valve, the gasket, and the discarded packaging film, and stole another look beneath the tool.
Flash—
One valve was still glittering. Not Valve 2, the one my senior had replaced. Valve 1.
"...Um, sir?"
"What, kid."
"Could I ask why the air valve on this tool was replaced? I heard it in the Inform, but I can't quite remember."
The Inform. The handover passed down from the previous shift—the work I had to do on this shift, and the things I would have to pass to the next. Saying I couldn't remember was a lie. I remembered it exactly. The Inform I'd heard from the worker before me.
WN-1. Looks like there's an air leak on the head side of Valve 1. We ran out of time and couldn't swap it, so get that replaced.
So the air valve that needed replacing was Valve 1. But my senior had replaced Valve 2.
Then that thing that keeps glittering...
Probably a sign that something was wrong. I didn't know why only my eyes could see it.
"Hey. You gonna get your head on straight? You're a new hire and you can't even memorize an Inform?"
"...I'm sorry. The WN-1 Inform was..."
"It was to replace it because of a head leak on Air Valve 1, wasn't i—"
He cut himself off, as if he'd only just caught his own mistake. Sigh. I'll have to go fetch another valve.
"I'll bring another valve."
"Why?"
"...Sorry?"
"The swap's done. Why would you bring another one?"
He said it without a shred of shame.
"Well..."
I started to answer and shut my mouth. Because you replaced Valve 2 by mistake, sir, and Valve 1 is still glittering. I could hardly say that.
"Let's go."
He walked off just like that. I stood there for a moment, blank.
...Is this really all right?
No. It wasn't. Heinrich's Law. Before one major accident, there are twenty-nine minor accidents of the same cause, and before those, three hundred near misses—warning signs that never become injuries. A statistical law. A law that teaches you the heart of preventing a catastrophe is ruthless control of the small accidents and the hazards.
In other words—
A small sign.
If the head leak wasn't prevented, a much bigger accident could follow.
"..."
Screw it. So I'd get chewed out. So what. I went straight to the parts cabinet, took an air valve of the same model, and picked up a wrench.
I just watched how the swap is done. I know.
It wasn't actually difficult. Loosen the fitting with a wrench, swap in a new air valve and gasket, and tighten the fitting again. The job was finished in under ten minutes. My senior was nowhere to be seen.
Flash—
The glitter on the tool was gone. In its place, the valve I'd removed was glittering.
...I think I'm right.
A broken part showed up to my eyes as a glint. I hadn't been born with this. As I'd said, it was something that had appeared out of nowhere not long ago.
Well. If it's useful, it's useful.
I shrugged. An ability like this wasn't going to cost me anything. If anything, it was better. I could spot a fault other people missed at a single glance.
All right, then...
I set up the next job. Once a part was replaced, you had to run a leak check. The process inside the tool ran at low pressure—in a vacuum, in other words—so there could be no leak in from outside. To verify that, a leak check had to follow every part swap.
Looks like he forgot, he was so flustered.
He was probably sitting at the engineer's computer stationed on the line by now. Having to run the leak check alone stung a little, but I was a new hire. This was nothing. I brought the equipment over quickly and started the check.
And then—
Beep-beep-beep—!
"...Huh?"
Valve 2, the one my senior had worked on, was showing a leak response.
Tsk.
I had no choice but to pick up the wrench again and tighten the fitting on Valve 2 once more.
Squeak—
The fitting turned more than half a rotation without my even putting force into it.
What?
Honestly, I was thrown. He'd left it this loose? It turned so easily I almost wondered if he'd done it on purpose.
That was when he came back.
"Hey! What the hell are you doing?!"
"Ah—sir."
I pulled myself out from under the tool and dipped my head.
"I ran a leak check and got a response, so I did some additional tightening."
"...On Valve 2?"
"Yes."
"You gonna lie to my face? Hand it over."
He snatched the leak-check tool, irritable, and sprayed it all over the place. This time there was no response.
"There's nothing. Where's this lie coming from?"
"..."
Of course there was nothing. I'd just tightened it.
"I'm sorry."
But a fragile new hire has to bow his head. For a while he huffed and lectured me about this and that. Yes, sir. Yes, sir. I let it pass.
"Anyway, clean up and come to the meeting room. We're doing the Inform."
"Yes, sir. Understood."
That meant today's work was over. I tidied the area and followed him toward the meeting room. On the way—
Flash—
That same glint, one more time. The one I'd seen while running dailies. Just in case, I glanced sidelong at the tool.
WN-3. Glinting from the lower section.
If I looked a little closer, I might be able to tell where the problem was...
"Hey! You coming or not? If the Inform runs late, you taking the blame?"
"Ah, sorry."
I hurried my steps again.
I'll remember it for now.
When we reached the meeting room, the next shift's seniors were already there, ready to take the Inform even though it wasn't time yet.
"Hello."
I bowed. They answered with a vague lift of the hand.
"Aigo, hyung. I'm really dying here. Because of this kid."
My senior treated them like friends and launched into a complaint—roughly, that he'd suffered because of me. The seniors flicked their eyes over the two of us.
Not exactly friendly.
It felt like my senior was the only one putting on the buddy act. Anyway, the brief small talk passed.
"I'll give the Inform."
His Inform began.
"First, the previous shift said WN-1 had a head leak on Air Valve 1, so we did the replacement. Leak check is complete as well. Just in case, please check the head leak one more time."
Slick as anything, he rolled the responsibility onto the next shift. Probably a hint to cover the mistake he'd made. Fortunately, the next crew wouldn't have to suffer. I'd already handled it.
"And..."
The Informs that followed. This tool had this problem. That tool had that one.
"That's all."
When the Inform ended, I raised my hand.
"Um, if I could..."
In an instant, every eye in the part landed on me. They clearly hadn't expected a new hire of less than a month to open his mouth during an Inform.
"It's about WN-3. I think there's some kind of issue."
The glint I'd seen earlier. That was what I told them.
"Reason?"
"...Sorry?"
"The reason."
The next shift's leader fixed me with a look and spoke.
"The reason is... uh..."
How could there be one? I'd only seen it glitter. If I'd had more time, I might have found it.
"I'm sorry. I'll study harder."
"Hm."
But his reaction was unexpected.
"Jihan. When you go in, run a dummy wafer on WN-3 first. Check the data, then put it into production."
"Yes, sir. Understood."
He'd believed me. No reason behind it. Nothing but the gut feeling of a new hire who hadn't been here a month.
"...Aigo, hyung, why go as far as a dummy? Just run it. They're already raising hell that output's down these days."
My senior said it while cutting me a sidelong glare. But the leader, Senior Jeong Woohyeon, shut him down in a single line.
"If there's an accident, you taking the blame?"
"...What? Ah, no. It's not that, but..."
"Then don't worry about me running a dummy, and get ready to clock out. We're late."
My senior stood there awkwardly, then bowed his head. On the way back to the office with me, he spoke again.
"...If you had something like that, you should've told me."
"Ah, yes. I'm sorry."
I dipped my head. And yet, somehow, I didn't feel bad.
I'm looking forward to tomorrow.
More than wasting feeling on something petty, I was looking forward to tomorrow's Inform on WN-3.