Cohost writing prompt: @Making-up-Mech-Pilots — Mech Pilot who climbed out of the OMEL-45
On a cosmic scale, in both space and time, the Earth is passing through the blast cone of some far-off civilisation-sized shotgun, and its buckshot is Bracewell probes. Tiny impactors carrying a bootstrap nanotech phase that, if it beats the odds and hits something in the vastness of space, eats enough local matter to build stage 2, which both self-replicates and builds stage 3, et cetera, and hundreds of steps later you have a huge crater in Ohio crawling with sentient alien robots, slithering in a silvery sea of nanotech that aims to exponentially spread and mechanoform the entire planet.
Containment is time-sensitive, but they got on location and crop-dusted it with smart dust that borrows from viral attack techniques to bind to and physically jam the operational mechanisms of several key nanotech strains; they unreeled the forcefield cordon fencing, ran it off emergency generators until the tok-in-a-box airlifted in and finished booting.
Now it's just another cleanup site, to be doused in antinanite spray every week from now until everything inside the cordon goes dead, and the emergency forcefence is officially designated Ongoing Mechanoforming Exclusion Limit, Site 45.
Which is fine, until the fucky stuff does something novel.
The big bipedal machine, when it stands up, has been exquisitely manufacture by the nanotech, but unlike its cousins, withering under state-of-the-art chemophysical attack, it's been built entirely from nanologically inert mechanisms: hydraulics, electronics, mechanical linkages. Tall enough to carefully step over the fence, while everyone shits bricks and starts yelling down the phone about authorisation for the last-ditch orbital strike platforms.
It sinks to one knee, and pops open a chest cavity that gets every weapon on site pointed at it, and out climbs—
"Don't move! Don't move!" Chartwell screams, thumbing the safety off her sidearm, pointing it at the emerging figure of...herself. Movements the same. Face the same. Hair the same length and parted the same.
Evil Fake Alien Fabricated Other Chartwell squints into the spotlights, raises her hands tentatively. "Hello?" she calls, sounding nervous and embarrassed. "Sorry. We really need to talk."