Seize the Night

cascade of whispery echoes returned to my ears from more than one direction.
    Bobby blinked at me.
    “Go ahead. Go on. With the barrel of the shotgun,” I prompted.
    “Strike it.”
    “It's glass,” Bobby protested.
    The extended sibilant at the end of his second word returned to us in a wash of echoes as susurrant as gently foaming surf.
    “If it's glass, it's not breakable.”
    Hesitantly, he gave the floor near his feet a gentle tap with the muzzle of the shotgun.
    A quiet ringing, like chimes, seemed to arise simultaneously from every corner of the huge chamber, then faded into a silence that was curiously pregnant with suspense, as if the bells had announced the approach of some power or person of great import.
    “Harder,” I said.
    When he rapped the steel barrel harder against the floor, the ringing was louder and of a different character, like that of tubular bells, euphonious, charming, yet as strange as any music that might be performed on a world at some far end of the universe.
    As the sound drained into another suspenseful silence, Bobby squatted in order to smooth one hand across the floor where he had rapped the shotgun barrel.
    “Not chipped.”
    I said, “You can bang on it with a hammer, scrape at it with a file, chop at it with an ice pick, and you won't leave the slightest scratch.”
    “You tried all that?”
    “And a hand drill.”
    “You're a destructive imp.”
    “It runs in my family.”
    Pressing his hand to the floor at a few different points around him, Bobby said, “It's slightly warm.” Even on hot summer nights, the deep concrete structures of Fort Wyvern are as cool as caverns, cool enough to serve as wine cellars, and the chill sinks deeper into your bones the longer you haunt these places.
    All other surfaces within these warrens, other than those in this ovoid room, are cold to the touch.
    “The stuff is always warm,” I said, “yet the room itself isn't warm, as if the heat doesn't translate to the air. And I don't see how this material could retain heat more than eighteen months after they abandoned this place.”
    “You can almost feel … an energy in it.”
    “There's no electrical power here, no gas. No furnaces, no boilers, no generators, no machinery. All stripped away.”
    Bobby rose from a squat and walked deeper into the chamber, playing his flashlight over the floor, walls, and ceiling.
    Even with two flashlights and the unusually high refractivity of the mysterious material, shadows ruled the room. Tracers, blooms, girandoles, pinwheels, lady ferns, and fireflies of light swarmed across the curving surfaces, mostly in shades of gold and yellow but some red and others sapphire, fading to oblivion in far dark corners, like fireworks licked up and swallowed by a night sky, dazzling but illuminating little.
    Bobby said wonderingly, “It's as big as a concert hall.”
    “Not really. But it seems even bigger than it is because of how every surface curves away from you.” As I spoke, a change occurred in the acoustics of the chamber.
    The whispery echoes of my words faded away, swiftly became inaudible, and then my words themselves diminished in volume. The air felt as if it had thickened, transmitting sound less efficiently than before.
    “What's happening?” Bobby asked, and his voice, too, sounded suppressed, muffled, as though he were speaking from the other end of a bad telephone connection.
    “I don't know.”
    Although I raised my voice almost to a shout, it remained muffled, precisely as loud as when I'd spoken in a normal tone.
    I would have thought I was imagining the increased density of the air if I hadn't suddenly begun experiencing difficulty breathing.
    Although not suffocating, I was afflicted severely enough to have to concentrate to draw and expel breath. I was swallowing reflexively with each inhalation, the air was virtually a liquid that I had to force down.
    Indeed, I could feel it sliding along my throat like a drink of cold water. Each shallow breath felt heavy in my chest, as if it had more substance than ordinary air, as though my lungs were filling with fluid, and the moment I completed each inhalation, I was overwhelmed by a frantic urge to get this stuff out, to eject it, convinced that I was drowning in it, but each exhalation had to be forced, almost as if I were regurgitating.
    Pressure.
    In spite of my rising panic, I remained clearheaded enough to figure out that the air was not being alchemized into a liquid but