Behind you, a pool of warm light lies under the windows of the glass-walled room that is the Trainmaster's Office. Little light, though, makes it past the platform's edge to the tracks themselves. They are long trenches of shadow between pale gray plateaus of concrete that stretch, tapering, into the middle distance, vanishing into more darkness. The rails themselves gleam faintly only close to where you stand: they too reach off into the dark, converging, and swiftly disappear. Red and green track guidelights shine dully there. A few shine brighter: the track crew members are down there, walking the rails to check for obstructions and wiping the lights off as they come. You walk quietly down the center platform, letting your eyes get used to the reduced light, until you come to where the platform ends, almost a quarter-mile from the arches of the gates. You jump down from the tapered end of the platform, into shadow, and walk out of reach of the last fluorescent lights. The red and green lights marking the track switches are your only illumination now, and all you need. Seventy-five feet ahead of you, Tracks 25 and 26 converge. Just off to your right is the walkway to a low concrete building, Tower A, the master signaling center for the terminal. You are careful not to look directly at it: the bright lights inside it, the blinking of switch indicators and computer telltales, would ruin your night-sight. You pad softly on past, under its windows, past the little phone– exchange box at the tower's end, on into the darkness. The still, close air smells of iron, rust, garbage, mildew, cinders, electricity—and something else. Here you pause, warned by the senses that drew you here, and you wait. Trembling on your skin, and against your eyes, is a feeling like the tremor of air in the subway when, well down (he tunnel, a train is coming. But what's coming isn't a train. Everything around is silent, even the subway tunnel three levels below you. Two levels above you now is the block between Forty-ninth and Fiftieth Streets: from there, no sound conies, either. Watching, you wait.