The Yandere villainess loves the useless engineer

I finally felt like I could think again.

The war with the Magneto Kingdom still consumed the borders. Supply caravans crossed through the territory constantly carrying weapons, armor, food, and medicine toward the front while wounded soldiers returned in the opposite direction. Rumors about stronger Magneto mages appearing near the battlefield spread through towns almost weekly now, and every forge within the Aldric territory had been pushed into military production.

But despite the war continuing—

I had finally gained a little breathing room.

Lillith had returned to the academy, Alex remained stationed at the border, and nobody had attempted to kill, kidnap, or emotionally overwhelm me for nearly a week.

That alone felt unnatural.

The shack still sat hidden deep within the forest exactly where it always had.

Far away from towns.

Far away from roads.

Far away from the industrial district.

Finn and I intentionally kept it isolated even after the steel production complex began operating. The workshop was where we experimented, built prototypes, and tested unstable inventions.

Keeping that kind of work far away from workers and settlements felt safer for everyone involved.

Especially Finn.

I stepped through the workshop door.

The inside looked horrific.

Metal scraps covered the floor while half-finished engine parts occupied nearly every surface. Pipes leaned against the walls beside stacks of sketches and mechanical diagrams. Several cast iron components sat near the furnace waiting to be refined further.

At the center of the mess stood Finn holding a bent steel rod with visible frustration.

"...Why does this keep happening?"

I leaned slightly against the doorway.

"Because you keep heating the metal unevenly."

Finn looked up immediately.

"Oh."

Then his eyes narrowed slightly.

"You look less traumatized today."

"Lillith left."

Finn froze.

"She actually went back to the academy?"

"Yes."

"And she didn’t threaten to erase civilization before leaving?"

"...Not directly."

Finn slowly placed the warped rod down.

"That’s probably the healthiest relationship development you two have had."

I ignored him and walked toward the main worktable.

Large sketches still covered nearly the entire surface. Drawings of pistons, wheel systems, crankshafts, valves, and boiler assemblies were scattered everywhere beside measurements and calculations.

Finn followed behind me.

"So."

He pointed toward the papers.

"What are we building this time?"

I rolled one of the larger sketches open fully.

"A car."

Finn stared blankly.

"A what?"

"A self-propelled vehicle."

"That sounds expensive."

"It probably will be."

"That sounds concerning."

I pointed toward the middle section of the design.

"The steam engine powers the rear axle."

Finn leaned closer while squinting at the diagrams.

The sketch showed a long reinforced frame supported by four large wheels. Pipes connected a central boiler system into a piston assembly positioned near the rear.

Finn immediately pointed toward the large cylindrical structure.

"That part looks dangerous."

"It’s the boiler."

"That does not comfort me."

I grabbed one of the unfinished piston cylinders from the table.

"This is the piston chamber."

I slid the heavy rod outward slightly.

"Steam enters from one side and forces the piston forward."

Then I pushed it back inward.

"Afterward the valve redirects steam behind it, pushing it the opposite direction."

Finn slowly nodded.

"So it keeps moving back and forth."

"Exactly."

I pointed toward another section of the sketch.

"The connecting rod transfers that movement into the crankshaft."

Finn frowned instantly.

"You’re inventing words again."

"The spinning shaft."

"Oh."

"That rotation gets transferred into the rear wheels."

Silence filled the workshop for several seconds.

Then Finn slowly looked back toward the sketch.

"...That’s insane."

The next several days became entirely focused on construction.

Most major components arrived from the industrial district by wagon every morning. The blast furnaces and molding systems had changed manufacturing completely.

Instead of shaping every major part by hand, workers at the steel complex now produced rough castings using packed sand molds built around wooden patterns.

Wheel hubs.

Pipe joints.

Support brackets.

Engine housings.

Gear casings.

Molten iron from the furnaces got poured directly into the molds before cooling into usable forms.

The resulting pieces still required refining afterward, but compared to manual forging—

Production had become dramatically faster.

Some castings emerged warped.

Others cracked while cooling.

One entire wheel hub shattered in half after forming an internal flaw.

Finn stared down at the broken pieces scattered across the floor.

"...I think the furnace hates us."

"The cooling process was uneven."

"That sounds like a smarter way of saying it exploded."

The chassis became the first major section assembled inside the shack.

Long reinforced steel beams were riveted together into a rectangular frame while additional supports strengthened the underside. The steam engine and boiler together weighed enough that the structure needed heavy reinforcement just to remain stable.

The roads throughout the kingdom created another major issue.

Most were terrible.

Dirt paths.

Forest trails.

Uneven stone roads.

Without suspension the machine would shake itself apart.

I solved that using layered leaf springs.

Several curved strips of flexible steel were stacked together and mounted between the axles and chassis frame. The layered structure allowed the wheels to absorb impacts independently instead of transferring every shock directly into the vehicle.

Finn bounced lightly on one of the mounted assemblies.

"...That actually works."

"It should."

"You sound surprised."

"I’m always surprised when things function properly."

Wheel construction alone took nearly two days.

Large wooden wheel cores were shaped first before heated steel rims were fitted tightly around the outer edges. As the metal cooled, it contracted around the wood and strengthened the structure significantly.

The wheel hubs connected into rotating collars around the axle shafts using grease lubrication to reduce friction during movement.

One early test immediately failed after Finn mounted part of the rear axle incorrectly.

The entire assembly locked sideways before collapsing violently into a pile of scrap metal.

Finn stared down silently.

"...I blame magic."

"You installed it backward."

"Agree to disagree."

The steam engine remained the hardest part by far.

Even with improved steel production, creating a reliable boiler still felt dangerous.

Thick riveted steel plates formed the pressure chamber while reinforced seams attempted to contain expanding steam safely under heat. Pipes extended outward into valve systems designed to regulate steam flow into the piston cylinder.

If pressure built too high—

The boiler would rupture violently.

Finn became more uncomfortable the more I explained steam pressure.

"No sane person builds a machine that can explode from boiling water."

I tightened another fitting carefully.

"Progress requires sacrifice."

"That sounds deeply evil."

The piston assembly itself demanded incredible precision.

Too much space between the piston and cylinder walls caused steam leakage.

Too little space created enough friction to jam the entire mechanism.

Hours disappeared into grinding, polishing, testing, and adjusting individual components until the piston finally moved smoothly enough for consistent operation.

By the end of the week, the workshop barely resembled its original form anymore.

Pipes crossed the floor.

Gear systems sat half-assembled beside the walls.

Tools and measurements covered every available surface.

And near the center of the shack—

The vehicle finally stood upright.

The unfinished steam car looked massive compared to anything Finn and I had built before.

A reinforced steel chassis supported the boiler and engine assembly while thick wheels rested beneath heavy suspension mounts. Pipes connected the boiler into the piston system while the crankshaft linked directly into the rear axle.

It looked crude.

Heavy.

Industrial.

Finn slowly circled around the machine before stopping beside me.

"...Do you realize how much this changes things?"

I looked toward the unfinished vehicle silently.

Far beyond the forest, the war continued with cavalry, swords, siege weapons, and magic.

But standing inside the shack was something entirely different.

The beginning of a machine age.