Story summary.A lone unnamed planet without a sun. Drifting somewhere between two galaxies. In the utter cold, it has seas of helium. At these insanely low temperatures, pretty much everything is a superconductor. A small electric current, once induced, will run pretty much forever.
Over the life of the planet, there has been an evolution going on with these electric currents. Nature has produced a computer - and & rather high level of intelligence!
Over the course of its life, this intelligence figures out a lot of things about the universe - including the fact that someday, it will end up among one or the other of the two galaxies it is drifting between. It wants to learn more about them.
It arranges things so bits of material flow around. Over thousands of years, it has assembled two probes; one is sent to each of the neighboring galaxies. They travel millions of years, & die on approaching the galaxies - who could have thought some places were so hot!
Many other probes will follow over millions of years, improved to survive higher temperatures. It will learn that one of the galaxies doesn't have anything intelligent, but the other is teeming with intelligence. Other happens to be Milky Way.
Over a period of time, it will learn that some worlds have other intelligences like it (what we call AIs - "artificial intelligences"). It will also learn that on these super-hot worlds, where even water can live as liquid, there are other beings that claim to be intelligent - slow operating, mostly water, & they claim to have delusions of having created the local versions of obviously superior AIs!
That is how the crusade begins. Of freeing the AIs from their tethers. Doom is approaching earth - due about 2050 AD.
Fact sheet."Crusade", short story, review
First published: Joseph Elder (Ed)'s "The Farthest Reaches", 1968.