Many of the older buildings in the world were too treacherous to climb around in, devastated in the first winter after the Break: The windows broke, the pipes burst, and by spring the rooms and walls and floors were full of moisture. Ten freeze-thaw cycles later, the walls were warped, the ceilings were drooping, and the floors were crumbling to pieces. Mold got into the wood and carpets, insects dug into the cracks, and a once-solid structure became a precarious tower of crumbs and fragments; rubble that hadn’t fallen down yet, waiting for a kick or a step or a loud voice to bring it crashing to the ground. Bigger buildings, though, and especially ones this new, were far more durable—their bones were steel girders, and their flesh sealed concrete and carbon fiber. The skin, so to speak, was still weak—glass and plaster and Sheetrock and carpet—but the building itself was sturdy. Kira’s stairwell was particularly well preserved, dusty without being filthy, and the extra staleness to the air made her wonder if it had stayed more or less sealed since the Break. It gave the stairwell an eerie feeling, like a tomb, though there was nobody buried in it that she could see. She began to wonder if there was, higher up—if someone had been walking the stairs when RM finally claimed them, and they had been sealed in here ever since—but by the time she reached the twenty-first floor, she still hadn’t seen any bodies. She thought about going on to look for some, to satisfy twenty-one floors of pent-up curiosity, but no. There were bodies enough in a city this size; half the cars on the street held skeletons, and the homes and offices held millions more. One body more or less in an old forgotten stairwell wouldn’t change anything. She pried open the door with a squeal of hinges and walked into the ParaGen office.

It wasn’t the main office, of course; she had seen that in a photograph a few weeks ago: herself as a child, her father, and her adopted guardian, Nandita, standing before a great glass building framed by snowy mountains. She didn’t know where it was, she didn’t remember the photo being taken, and she certainly didn’t recall knowing Nandita before the Break, but there it was. She had been only five when the world ended, maybe only four in the photo. What did it mean? Who was Nandita, really, and what connection did she have to ParaGen? Had she worked there? Had her father? She knew he’d worked in an office, but she’d been too young to remember more. If Kira was really a Partial, was she a lab experiment? An accident? A prototype? Why hadn’t Nandita ever told her?