“Butterfly Bomb” by Dominic Green

A “story-sized set of reasons” why our universe might be a space opera universe, according to the introductory notes. Sadly, neither the story nor the set of reasons is particularly exciting. An elderly man, living alone on an alien world, hitches a ride on a passing slave ship (by selling himself into slavery) in order to track down his granddaughter: the main things we learn along the way are that (a) AIs tend to think themselves into logical-philosophical blind alleys, which puts a crimp in civilization’s style but creates jobs for those who, like the protagonist, can mediate such quandries; and (b) ancient races left behind AI-based weapons that can mimic, infiltrate and destroy any societies they encounter. It’s not as perfunctory as proof-of-concept tales can be, and Green’s playfulness mostly carries it —

The superintendent scratched his forty-year service tattoo thoughtfully. “In that case, you might be of help to us. Our own mediator had arranged a system of non-overlapping magisteria between the nihilist and empiricist factions in our ship’s flight systems, but we were infected with a solipsistic virus several days ago. The accord has now broken down into open sulking. Wehave been becalmed insystem for two days while our vessel argues with itself. Our astrogator is muttering cray talk about learning to use a slide rule.”

— but I’m still somewhat surprised to see it showing up in the table of contents for a best-of-the-year volume. (And “the bunks clearly built for Svastikas, a radially symmetrical race previously conquered by the Proprietors” was pushing it a bit.)