"Perfect."
Chromium 1 percent, molybdenum 0.5 percent.
An ultra-low-carbon steel base.
A miraculous alloy formula with a yield strength of 480 MPa—something that could be cast even in the crude furnaces of a fantasy world, yet would easily repel mana steam at 150 atmospheres.
The perfect heart of a steamship that would devour every shipping lane on the continent was now in my hands.
"Now all I have to do is go back and boil some molten iron."
I slipped into a narrow alley behind the research institute, where there were few signs of people.
After making sure there were no CCTVs or people nearby, I pulled out the Carnoble family pendant that had been hanging inside my shirt.
Tick, tick.
I gripped the mainspring at the center of the pendant between my thumb and forefinger and wound it with all my might.
Beyond Earth, to Pelua on the far side—to the temporary shipyard on the banks of the Rene River.
I had to return to that very instant, just before Aila screamed, the boiler's outer wall tore open, and the high-pressure steam exploded.
"Open."
I squeezed my eyes shut and vividly called to mind that desperate situation just before the explosion, along with Aila's voice.
I waited for the pendant to respond to my mental "yearning" and emit its blue light.
But.
"……?"
Even after one second, two seconds, ten seconds, the pendant remained nothing more than a cold lump of metal, not releasing even a single strand of light.
"Why is this happening? Is my yearning not enough?"
I tried winding the mainspring roughly again.
I put so much force into it that the tips of my fingers turned white from the lack of blood, but the gears were stiff and unyielding, as if crushed beneath a massive boulder.
At that moment, the mechanical engineering circuit in my head arrived at a single conclusion like a bolt of lightning.
"Ah…… damn it."
A cold chill ran down my spine.
I had overlooked the first condition for the pendant to open a dimensional gate.
[Reaching the critical point of an enormous amount of physical energy.]
"What was the energy that was injected into the pendant when I crossed over to the modern world?"
It had been a temperature of several hundred degrees Celsius, and the explosive expansion pressure of a boiler exceeding 150 atmospheres.
The pendant had absorbed that tremendous thermal energy and mechanical energy like a black hole, piercing through the dimensional wall.
"But right now, the destination I'm trying to return to is the space-time of that exploding 'instant.'"
To open the dimensional gate and reverse my way into that tremendous vortex of explosive energy, I too had to inject an overwhelming amount of physical energy into the pendant on my side, enough to break through the dimensional resistance.
But there was no way a few turns of the mainspring with a human's flimsy grip strength would generate hundreds of megajoules of energy.
"At this rate…… I can't go back."
My heart sank.
What if I couldn't return?
The time of that world, frozen at 0.1 seconds before the explosion, would begin flowing again the moment the dimensional connection was severed.
The house-sized boiler would burst apart, the workshop and shipyard would be reduced to ashes, and Aila, who had been standing right in front of my eyes, would be torn apart by thousands of cast-iron fragments and lose her life.
"No. I can't let that happen."
I clenched my molars and shoved the pendant into my pocket.
There was no time to despair.
I was not a magician, but a mechanical engineering student.
If I needed energy impossible to produce with human strength, then I just had to use a machine to force it into being.
"If I can't use pressure or heat, I'll punch through with rotational force."
I sprinted all the way and jumped onto the subway.
My destination was the Second Engineering Building of Hanguk University, the large machinery and heavy equipment training room.
Fortunately, the university training room on a Saturday afternoon was silent.
I swiped my security card and slipped into the empty, high-ceilinged training room, then ran straight toward the heavy machine in the corner covered by a waterproof tarp.
Fwoosh!
When I pulled away the dust-covered tarp, a huge dark silver cylinder as large as a person's torso revealed itself.
"A high-output industrial AC servo motor."
A monster usually used for dynamometers measuring automobile engine output, or when testing small turbines by spinning them to their limits.
A tyrant of electrical energy with an instantaneous maximum output reaching several hundred kilowatts, capable of producing insane rotational force of tens of thousands of RPM.
"I'm going to pour this thing's rotational force directly into the pendant's central gear."
I ran around the training room like a madman, gathering tools.
The servo motor's rotating shaft was as thick as an adult's forearm, while the pendant's central gear was smaller than a coin.
It was impossible to mesh the two as they were.
Zing—whirr!!
I immediately powered up the ultra-precision CNC lathe.
I clamped a solid tungsten carbide hexagonal pillar into the chuck and began personally machining a "special adapter coupling" that would connect the motor's massive shaft and the pendant's tiny cogwheel without even the slightest error in alignment.
Shaved metal chips flew in all directions, and hot cutting oil sprayed out.
Beyond my safety goggles, only the blueprint's measurements flashed in my eyes.
"There can't be even a single micrometer of play. If the rotational axis shifts, the pendant will be ground away."
In a miraculous thirty minutes, I finished machining the adapter and firmly bolted it to the servo motor's shaft.
Then I drove a massive industrial vise into the training room floor with anchor bolts, lined it with rubber pads so the pendant wouldn't be scratched, and clamped the pendant tightly in place.
The motor's adapter and the pendant's mainspring gear meshed perfectly, like cogwheels.
"Setting complete."
I wiped my sweat-soaked face with my sleeve and stood before the motor's control panel.
My fingers were trembling.
This was an insane gamble that could very well blow up the university training room.
But in my head, there was only Aila and Pelua's factory.
"Let's go."
Click.
I turned on the main power and slowly rotated the dial.
Wooooooooong—!
As power was supplied to the enormous servo motor, a heavy operating hum shook the training room floor.
5,000 RPM.
The motor spun, and the adapter began forcibly winding the pendant's central mainspring at a crazed speed.
Kiiiiiiik!
The pendant screamed, and the gears inside spun so fast they left no afterimage at all.
At the same time, a faint blue light began leaking from the gaps in the pendant.
"Good, it's taking! Higher!"
I jerked the dial hard.
10,000 RPM. 15,000 RPM!
Wheeeeeeeeeeng—!!
A high-frequency noise like tearing air filled the training room.
The blue light grew thicker and thicker, and a haze rose as though space itself were warping.
But just before the dimensional gate opened, the pendant's true power bared its teeth.
That overwhelming "dimensional resistance" from reversing into the space-time just before the explosion had converted into a physical load and begun clamping down on the motor like mad.
"Urgh……!"
The control panel's alarm screamed wildly.
[Beep—beep—beep—! OVERLOAD WARNING!]
The motor's RPM was forcibly dragged down, and the amperage reading shot up insanely as it tried to push itself beyond its limits.
As the current ran wild, the thick power cables writhed like snakes, and black smoke began rising from within the motor coils along with an acrid burning smell.
"No! If the motor stops now, it's all over!"
That was when it happened.
Tuk, tuk.
The fluorescent lights in the training room began flickering violently.
"Damn it!"
The circuit breaker in the distribution panel for the entire engineering building had recognized the abnormal overcurrent the servo motor was sucking in as a fire hazard and was about to blow the fuse.
If the power was cut, it was over.
The motor would stop, and the dimensional gate would be closed forever.
"Who said you could cut the power!!"
Eyes rolling back in desperation, I snatched up insulated rubber gloves and pliers and ran to the large main distribution board on the wall of the training room.
Clank!
When I yanked open the metal door, the huge magnetic circuit breaker, boiling with heat from the overload, was on the verge of tripping at any moment.
In my deranged mind, the "safety rules" of an engineering student had already evaporated.
I stood before three-phase AC power lines carrying thousands of volts, enough to turn me into a lump of charcoal on the spot if I were electrocuted.
"It's do or die. Bypass!"
I ripped out the breaker's safety circuit with the pliers and smashed it apart, then forcibly shoved the three thick main live wires into the wiring leading to the motor controller, directly "hardwiring" them together.
It was an insane act that completely castrated the safety devices and poured the entire building's massive electrical power solely into that one motor.
Crackle! Paaaah!
Blue sparks burst from the distribution board and burned my work clothes, but I did not back down and pressed the wires down hard.
"Spin! Spin more! Please!!"
Freed from its safety limits, the servo motor let out a thunderous roar as if it were about to explode.
20,000 RPM!
Rrrrrrrumble—!!
The motor's outer casing heated red-hot and began to catch fire.
Only a few seconds remained before the internal coils melted and the circuit broke.
At last, a massive crack began forming in the dimensional wall pressing down on the pendant.
"Open!!"
Clutching the sparking distribution board, I screamed as if weeping blood.
"Aila, my factory, my steel monster—I have to get back before they blow up! Send me to Pelua!!!"
My vicious greed to tear apart this world's trade routes, and my engineering yearning.
That explosive mental energy resonated perfectly with the physical mechanical energy of the runaway motor swallowing the entire building's power in one gulp.
Ziiiiiiiiing----!! Kwaaaaang!!!
At the same time as the high-output servo motor, unable to endure any longer, shattered into pieces and exploded with a deafening roar.
From the pendant clamped in the vise, a dazzling blue flash erupted as if it could swallow even the sun.
"Graaagh!"
The flash engulfed my body, and the scenery of the engineering building training room shattered like a pane of glass.
A distant sensation, as if all my senses were being hurled into weightlessness.
And then.
Chiiiiiiik—! Craaaaaack!!
The instant my vision returned, the chilling sound of metal tearing apart, loud enough to rip my eardrums, slammed into my ears.
The heat like roasting flesh, the acrid, fishy smell of steam.
"C-Chief Merchant! The boiler's outer wall! The iron plate is tearing!"
"Everyone evacuate! It's going to explode! Get down!"
The urgent scream burst from my mouth.
I was hanging on, both hands tightly gripping the boiling-hot main valve in the control seat.
Before my eyes, the very same horrific scene I had seen just before leaving Pelua was unfolding with not a single deviation, as if time had been paused.
The two-inch-thick cast-iron plate was bulging, the grease in the seams was melting, and steam several hundred degrees Celsius hot was gushing out—the very instant exactly "0.1 seconds before" the boiler fragments scattered in all directions!
"I…… came back."
I tightened my grip on the valve, bared my teeth in the flames of the explosion, and smiled like a beast.
"Elpansoooooo—!"
I saw Aila's tear-soaked face as she screamed and ran toward me.