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English
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Published:
2026-03-29
Updated:
2026-04-11
Words:
16,907
Chapters:
12/?
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Sunk Cost Fallacy

Summary:

It turns out that being wired into a giant war machine doesn’t play nice with human brains. The Earth Mechanical Defense Force, or EMDF, learned that the hard way when their pilots started going… neurotic, let’s say, after a few missions.

The obvious solution to that problem was to simply wire the pilot into their mecha permanently, that way their mind wasn’t being strained by the constant in and out. Unfortunately that strategy backfired and the pilots started going neurotic much, much faster, and this time they were giant and made of metal and much harder to put down.

So, the obvious next step would be to pull the plug on that idea and go back to the drawing board, right? No, that’s ridiculous, the next step was obviously to simply…

Make the mecha forget they’d ever been human in the first place.

Somewhere along the line someone should have pulled the plug, but they’d already invested so much into the project, and you know what they say about sunk cost fallacy.

Notes:

Please, please go read The Unknown Universe and its sequel and give the author lots of love. They’re absolutely incredible fics, and this fic was born from me theorizing about the story and worldbuilding of those fics after reading them.

Chapter 1: Home

Chapter Text

Jazz cycled his vents heavily as he backed away from the leviathan’s corpse, working to cool his frame. It was midday, and the sun beating down on his dark paint wasn’t exactly helping with that goal, but ultimately it wasn’t a major hindrance. More an annoyance than anything else. He scanned the rocky beach for any lingering quints but couldn’t find any. Pleased with a job well done he sheathed his sword and let himself have a moment to shake some of the alien blood and goo off before-

A familiar, low buzz began to build in the back of his helm

wrong wrong wrong wrong

and he resisted the urge to claw at it. It wouldn’t do anything, the homing beacon was built right into his processor, if he tried to claw it out he’d just kill himself

he’d tried before anyway.

The only way to make the buzz go away was returning to base, they’d shut it off once he got back. As he started heading for it he let his nav computer do most of the work so the rest of his processor could wander a little. He’d done an excellent job this time, taking down the leviathan before it could fully get out of the water and only obtaining minimal damage. The engineers would be pleased to have less work. Major damages were always particularly tedious to repair.

The quints had shown up fairly close to the base this time around so it wasn’t a long trip, only about twenty minutes of sprinting, and soon he was sliding into the first empty slot in the return bay. He had to get down on all fours to do so

he wasn’t a fucking animal, this was degrading

since the bay ceiling wasn’t tall enough to accommodate him if he was standing upright.

The heavy weight of the guideline’s anchor settled around his neck as similar anchors wrapped around his wrists and ankles, holding him still while the maintenance crew gave him a rinse down, took his weapons, and noted down any visible damage for the engineers. He let himself relax into the post mission bath, the buzzing in his helm fading away now that he was home.

A nice, hot bath had always felt so good after a long day.

Unfortunately his peace was soon broken as a commotion coming from the concrete field that formed the center of the Las Vegas EMDF base drew his attention. His audio receptors twitched forward in interest. 

The humans liked to joke that it made him look like an excited dog and every time they did something deep in his processor died a little more.

One of the other mechas, Bumblebee was his designation, was fighting hard against the guidelines, digging his claws into the concrete and thrashing. One of his legs kept spasming at random and the engineers were trying to bring him to the maintenance bay to fix it. A broken leg could be a death sentence in the field after all.

Jazz felt a pang of empathy as he watched. Bumblebee was the newest mecha, only a few months old. He was still young and scared of everything like most young things were

like he’d been when he was still small and squishy and easy to harm, back before he’d woken up made of metal and wires and whatdidtheydotome-

Maintenance wasn’t pleasant, but fighting would ultimately end with a forced shutdown, which was far worse than just going along with it.

Sure enough, a moment later Bumblebee’s frame seized and he dropped, limbs twitching for a moment longer before they went still. He was going to have such a bad helmache later, hopefully the younger Mecha learned from this. Jazz had been stubborn when he was new and in hindsight all his fighting hadn’t been worth it.

Screaming with his body because he couldn’t scream with his voice.

He gave his helm a little shake in an attempt to chase away the glitchy, half formed thoughts trying to clog up his processor. After his bath he’d be going to maintenance and while he usually had a helmache after

from them digging and tearing and downloading and treating his brain like a computer

at least those strange, glitchy thoughts wouldn’t bother him for a while.

Sometimes he wondered about them, in the quiet of his docking bay before he recharged. There was no logical explanation 

yes there was

for the glitches, the half formed thoughts and images that felt horribly familiar despite the fact that he had never seen any of the people in them before

he had he had he had he’d grown up with them.

Why would he have images in his processor of a school? He’d never gone to school, there’d never been any need. If he needed to learn something it was simply downloaded into his processor during maintenance. Besides, he wouldn’t even fit in a tiny human classroom, he was far, far too large.

He’d once been so small.

So why, then, did he have so many images in his processor of the inside of those classrooms, surrounded by

other

children and teenagers?

The anchors around his limbs released and the guidelines attached to the anchor around his neck were tugged forward,

I’m not a dog

the machinery beneath the concrete that moved them just barely visible through the cracks that allowed the lines to travel. Sure enough, just as he’d expected he was led to the maintenance bay and into an open slot. New anchors secured around his limbs and he slid his head between the thick pillars in front of him so the neck anchor

collar

could lock to them.

As the engineers began working over the damages to his frame he looked to the side. Bumblebee had come back online and for some reason

you know why

his whole frame was shaking. Maybe a lingering effect of the forced shutdown? Jazz remembered that he’d felt fairly shaky after the first couple of times that had happened to him. 

Clawing clawing clawing at his own helm, trying to get them out they shouldn’t be in there, shouldn’t be in his mind

Geez, how long ago was that now? A decade? That seemed about right. Poor kid. Hopefully he learned quickly, Jazz would hate to see him get shut down before he was even a year old.

THEY SHOULDN’T HAVE TO FEAR BEING EUTHANIZED LIKE ANIMALS THEY WEREN’T ANIMALS THEY WERE PEOP-

There was a small click as one of the engineers plugged into his processor, and Jazz was pulled down into the darkness.

Some part of him wailed the whole way down.

 


 

Jazz came online to a low grade helmache, exactly what he’d expected. At least his processor was quiet now without all the glitches trying to drown it in their nonsense. He’d take the maintenance helmache over that any day, especially since the glitches often came with their own, even worse, helmache.

Sitting up he onlined his optics to peer through the two foot thick, reinforced glass that made up the door of his docking bay. Across the hallway Bumblebee lay in an identical bay, back to the glass. There was no movement, meaning he must have still been recharging. If he’d offlined the humans would be all over the empty frame.

In the docking bay to the left of Bumblebee’s, Sunstreaker was up and pacing. The ceilings were too low for them to stand upright so he was down on all fours, circling around and around in that way he always did when Sideswipe was on a mission and he wasn’t. The humans often called them “twins,” whatever that meant. Usually they were deployed together, but occasionally they’d be sent off alone. Neither of them liked when that happened.

Deploying them together was the smartest choice, their efficiency dropped notably when separated. Whatever mission Sideswipe was on must not have been too dangerous if that drop in efficiency had been deemed acceptable, so he’d likely be back soon. Then he and Sunstreaker could return to staring at each other across the hall with their facial plates pressed against the glass of their doors. Jazz had no idea why that was their favorite pastime, but it was.

His attention was pulled back to Bumblebee when the yellow and black mecha shifted, sitting up a moment later. He didn’t turn around, unfortunately, instead just staring at the tiny window high up on the back wall. All the docking bays had it, allowing the mecha to see a sliver of sky when they weren’t deployed. Jazz thought it was quite kind of the humans to give them that luxury.

Seeing the sky shouldn’t be a luxury.

Oh. The glitches were back.