I am alone now. I don’t know who else survived.
We think it started in a lab. A team of scientists wanted to create a self-replicating machine, just to see if they could. They stored the program in a polymeric ribbon; they made the machine out of carbon, not silicon, so that it posed no threat to life. The team published a paper, sterilized the vat, and flushed the waste down the drain.
It shouldn’t have survived. It shouldn’t have mattered — the scientists assumed the machine would find nothing to feed on in our world. They were wrong: it found meager sustenance near a deep-sea geothermal vent. It couldn’t have lasted — fragile carbon bonds inevitably fall apart. What the team didn’t realize was that once in a million, the damage didn’t break the program; it just altered what it did.
That’s how we found out: it had somehow learned to fix carbon from the air. We spotted a gigantic patch of green slime drifting in the ocean, surrounded by a cloud of corrosive oxygen gas. We studied it, but it took us years to trace it back to the lab. Then another colony washed ashore. And then more.
We tried to stop it, of course. We developed a metal complex that interfered with the transcription process; it worked until the machines learned to envelop the molecule in a carbon-nitrogen cage. We tried dozens, no, hundreds of other tricks. No matter what, the slime always bounced back — an unthinking, unstoppable mass that slowly suffocated the oceans and poisoned our air.
We thought we had time; we were the masters of our domain, the slime was just a bothersome pest. And then, without warning, the swarm figured out how to cleave the siloxane bond. It didn’t have a reason, we don’t think. A robotic slime has no wants; it just is. One by one, the mass tore apart every living creature, turned every city to dust.
Thick layers of silicon dioxide now blanket the Earth and cover ocean floors. I hope for a miracle; without it, this may be all that remains of intelligent life.
Other short stories: severance, zombies, multitudes, eternal life, the rapture, a new beginning, true love, the review.