“It hadn’t worked out that way. Even if we’d outgrown the need to stay quiet and hidden during the dark hours—the only predators left were those we’d brought back ourselves—the brain still needed time apart from the world outside. Experiences had to be catalogued and filed, midterm memories promoted to long-term ones, free radicals swept from their hiding places among the dendrites. We had only reduced the need for sleep, not eliminated it—and that incompressible residue of downtime seemed barely able to contain the dreams and phantoms left behind. They squirmed in my head like creatures in a draining tidal pool.”