There was something about him that was different than the others, too. Not that he looked all that different. The glowsticks were all a bunch of ugly bastards, and over the six months Grey had been working on Level 4, he’d gotten used to their appearance. There were little differences, of course, that you could pick up if you looked hard. Number Six was a little shorter than the others, Number Nine a little more active, Number Seven liked to eat hanging upside down and made a goddamn mess, Number One was always chatting away, that weird sound they made, a wet clicking from deep in their throats that reminded Grey of nothing.

No, it wasn’t something physical that made Zero stand out; it was how he made you feel. That was the best way Grey could explain it. The others seemed about as interested in the people behind the glass as a bunch of chimps at the zoo. But not Zero: Zero was paying attention. Whenever they dropped the bars, sealing Zero on the back side of the room, and Grey squeezed into his biohazard suit and went in through the air lock to clean up or bring in the rabbits—rabbits, for Christsakes; why did it have to be rabbits?—a kind of prickling climbed up his neck, like his skin was crawling with ants. He’d go about his work quickly, not even really looking up from the floor, and by the time he got out of there and into decon, he’d be glazed with sweat and breathing hard. Even now, a wall of glass two inches thick between them and Zero hanging so that all Grey could see was his big glowing backside and spreading, clawlike feet—Grey could still feel Zero’s mind roving around the dark room, trolling like an invisible net.

Still, Grey had to say it wasn’t a bad job on the whole. He’d certainly had worse in his life. Most of the time all he did was just sit there through an eight-hour shift, penning his way through a crossword and checking the monitor and logging in his reports, what Zero ate and didn’t eat and how much of his piss and shit went down the drain, and backing up the hard drives when they maxed out with a hundred hours of video footage of Zero doing nothing.