That sense of instability manifested as a constant nervous energy. Every winter, every weekend, could be one person’s last and another’s first. It made Anna and Tom feel alive, fueled their curiosity and sense of adventure, and reinforced the impression that the city was inexhaustible. And yet their world was smaller now than it had been when they were students. At any given time there were, at most, a dozen or so people they saw on a regular basis, and the liminal circle of vaguely familiar faces and half-acquaintances was looser and more ill-defined than it had been at university. Not that they ever noticed, because that limited world regenerated fast enough to give the illusion of infinity.