As always the variation in life-forms across the cosmos was extraordinarily wide, but most shared certain basics of their physical design. Almost all of them stored information about themselves in their own complicated structures, rather than in an internal genetic data store, as humans one day would: for these creatures their genotype was their phenotype, as if they were made wholly of DNA.

Their way of communicating would have seemed ferocious to a human. A speaker would modify its listener’s memories directly, by firing quagma pellets into them; it was a message carried in a spray of bullets. They even reproduced rather like DNA molecules. They opened out their structures, like flowers unfolding, and constructed a mirror-image version of themselves by attracting raw material from the surrounding soup of loose quarks. These “quagmites” were not quite like the creatures humans would one day encounter in the Galaxy’s Core, but they were their remote ancestors.

There was little in common in the physical basis of human and quagmite; a quagmite was not much bigger than an atomic nucleus. But the largest of the quagma creatures were composed of a similar number of particles to the atoms which would comprise a human body. So humans and quagmites were comparable in internal complexity, and their inner lives shared a similar richness. Many humans would have appreciated the best quagmite poetry—if they could have survived being bombarded by it.

Meanwhile, the quagmite creatures shared their universe with older forms of life.

The ancient spacetime-chemistry creatures, having survived yet another cosmic transition, gradually found ways to accommodate themselves to the latest climate, even though to them it was cold and dark and dead. In their heyday there had been no “matter” in the normal sense. But now they found they could usefully form symbiotic relationships with creatures formed of condensate matter: extended structures locked into a single quantum state. A new kind of being ventured cautiously through the light-filled spaces, like insects with “bodies” of condensate and “wings” of spacetime defects. It was the formation of a new kind of ecology, emerging from fragments of the old and new. But symbiosis and the construction of composite creatures from lesser components were eternal tactics for life, eternal ways of surviving changed conditions.

In the unimaginably far future humans would call the much-evolved descendants of these composite forms “Xeelee.”

The proto-Xeelee were, meanwhile, aware of another species of matter born out of this turbulent broth. This would one day be called dark matter by human scientists, for it would bond with other types of matter only loosely, through gravity and the weakest nuclear force. There was a whole hierarchy of particles of this stuff, even a sort of chemistry. This faint stuff passed through the quark-cluster cities and the nests of the proto-Xeelee alike as if they didn’t exist. But it was there—and, like the Xeelee, this dark matter was going to be around for good.