At 2:07 a.m., the river kept its own counsel. Fog braided low between the pilings of the old steel viaduct, and the faint amber sheen of the town's sodium lamps turned the water the colour of tea. Mara pedaled slowly along the cracked river road, a canvas satchel slung across her back, the strap creaking with the weight of microphones and cables. She had been a child of this river-the mills, the rail spur, the cutbanks where spring floods chewed the earth-and she had left before she was old enough to vote, vowing never to return. Then she had returned anyway, years later, when the mills shut down and the town went quieter, and she found herself unable to shake the habit of listening for small sounds: the rasp of a toad at dusk, the sharp shoulder of a fox at 3 a.m., the silk-whisper of bat wings skimming a streetlight. She took the night shifts at the wildlife clinic, stitched split wings, syringe-fed orphaned raccoons, and learned to identify birds by the feel of their bones beneath her fingers. Tonight she wasn't headed to the clinic. She was out because of a time and a tone. Twice now, in spring and midsummer, at exactly 2:17 a.m., she had watched the entire river valley hold its breath. Her field recorder, an old silver box with a cracked display, had captured a ladder of tones that arced into frequencies she could not quite hear-pressure more than sound. Her neighbours had laughed about it at the diner, as if she had been taken in by static from the substation or a train braking on a far-off grade. She'd laughed too, until she noticed the animals. The animals didn't laugh. They listened. Mara coasted to a stop where the road bent under the viaduct. The bridge was a rib cage of steel and rivets, its belly shadowed and high. The pilings wore graffiti like badges: declarations of love, sneaker scuffs, the ghost of a painted halo over a boy's name. The river's surface moved as if something were breathing just below it, a slow collapse and release she had told herself was only current hitting the concrete. She swung off the bike. The fog dampened the world into velvet. She could hear the drip of condensation from the bridge, the glassy clatter of shells in a raccoon's paws, the soft pad of a cat in dry weeds. Her recorder's screen buzzed to life. She clipped a shotgun mic to the guardrail, then lowered a hydrophone-two lengths of cable coiled like eels until the lead weight tugged her wrist and disappeared into the black water. She checked the time. 2:13. "Back again?" A voice like a coin tossed into a well. Mara looked up, but she knew that voice without seeing. High on the flanged beam, a raven sat tucked into his own shadow. His right wing bore the faint kink of an old fracture, set in her hands last winter after a storm had thrown him into a fence. She had named him on the intake form, though she knew better than to name wild things. He'd kept the name anyway, or at least the part of it she'd spoken softly while she taped splints and fed him mice thawed in warm water. "Hello, Gleam," she said. "You picked a clear night." Gleam cocked his head. A necklace of droplets hung from the beam like glass beads. Somewhere under the bridge another bird moved-shifting toes, feather against steel. Beyond that: traffic a half-mile away; a train horn farther than that. Gleam's eyes were not audio spectrograms or wavering green lines, but Mara had come to trust the way he watched the world. He ruffled his thick neck feathers and made a sound like a cork turned in a bottle. It was not a greeting. It sounded like readiness. At the edge of the road, a red shape paused and then stepped into the halo of the lamp. The fox stood sleek and narrow, the white tip of his tail like a paintbrush dipped in light. He was one of the river foxes, the ones who learned to wait under the iron bridge for pigeons to drop. Mara had seen him in daylight once, loping along the floodwall with something bright in his mouth-a candy wrapper, maybe a scrap of foil-and when she spoke to him he had flicked an ear in her direction as if replying was beneath his dignity. She had called him Bracken, because names were nets and he had slipped every one she tried until he let that one catch. "Good evening," she said. Bracken's regard was not human and did not try to be. He sniffed the air, nose high, and then trotted to the water's lip, careful not to look at her. He set something down and backed away. When Mara crouched, she found a piece of green glass worn smooth, pierced cleanly as if by a drill. River glass didn't come bored like that. She put it in her pocket without thinking why. Out in the dark, movement stitched the riverbank: two raccoons, ringtails like punctuation, sat up on their haunches to stare toward the current; a line of deer eased out of the cottonwoods, moving not from fear but from decision; the stray cats in the old pump house window arranged themselves along the sill like a row of saints and watched with their pupils huge as coins. Crows crowded the girders by the dozen, black on black. Gleam sat apart. Mara checked the time. 2:16. She heard it before her recorder did: the faintest tightening of the air, a whisper of pressure that turned the hairs on her arms to needles. The display answered a second later with a green flame at the edge of the band she'd learned to watch. The hydrophone line thrummed gently against her wrist. Across the river, the lights in the mill's broken windows flickered and steadied, as if someone walked a corridor turning switches on and off. The deer lifted their heads in the same breath. Even the raccoons stopped their low mutter. The world bent towards a sound she could almost but not quite hear. It wasn't an engine. It wasn't a wind. It was layered, clean, tuned to a purpose she could not name. "Okay," Mara said to no one. Her voice sounded foolish and small under the bridge. "Okay." Gleam dropped from the beam and landed beside her with a hop, claws clicking on the guardrail. He looked pointedly towards the maintenance gate that hung chained but not locked, one hinge singing quietly. Bracken darted ahead, slipped through the gap in the chain, and paused inside to watch Mara with that profile that was all intent and no explanation. If the animals had all run, she would not have followed. It was the steadiness that undid her. The deer did not flinch when she moved; the crows only breathed. She lifted the chain, slid into the narrow stairwell that laced downward through the viaduct's spine, and felt the wet cold of the metal seep through her jeans. Drops rang on the steps like spilled beads. She moved slowly. Gleam chose to walk, wings closed, talons careful on the grating close to her shoulder. Under the bridge, the air changed. The river's mutter became a body. It pressed soundlessly against her chest until her heart had to find a new place to beat. The hydrophone line paid out over the rail and quivered as the weight reached for depth. Around her, animals appeared out of the gloom the way memories do: a possum along the lower beam, a nighthawk clinging to a brace, an owl that turned and did not lift when she came to the landing. Their eyes took the light and gave it back different. Mara set the recorder on a step and watched the jagged ladder of sound rise, step by bright step, the peaks like a cathedral built out of breath. She had always believed that if she could hear the whole of it, unhidden by the limits of her body, it would be both terrible and beautiful. She didn't know why she put those words to it-terrible like a flood line, beautiful like a winter sky so cold it burned your teeth. The deer arranged themselves along the platform, their ears like flags, their bodies aligned towards a point in the black water. Bracken paced once along the rail and stopped again, nose high, tail still. Gleam leaned into the stairwell and gave a single voice, a sound that slid across the frequencies like a skater stepping from new ice to glass. Mara pulled the green glass from her pocket and held it up. It made a small lens through which the bridge was both more and less. Through it, the rivets became stars. Through it, the fog made a ring. "Is this a door?" she said, not expecting an answer. The recorder's levels trembled, dipped, steadied. The hum tightened and lifted, a wire drawn taut. Something answered anyway, but it was not a voice. The surface of the river, black and near and not a surface at all, shivered as if a hand had passed just beneath it. A faint light-no more than the reflection of a faraway streetlamp-seemed to double and draw down, to gather itself. The current, which had always flowed one way here, hesitated. It seemed suddenly to travel toward them as well as away. Gleam sidled closer until his shoulder brushed her coat. He ticked his beak twice against the green glass. A closed syllable. Bracken stepped forward, set one forepaw on the ledge, and did not look at her. A raccoon sat back and lifted its hands, as if to warm them at an invisible hearth. Mara's recorder printed the night into a thing that could be kept. But what she heard bypassed the part of her that kept things. It threaded her, the way cold water threads the ribs and you shiver while your skin pretends to be warm. The lights across the river flickered again-once, twice-and then the windows went dark as if a blanket had been thrown over the town. 'Do you want me to-' She didn't know how to end the sentence. Step back? Step forward? Ask a question with no words in it? The green glass in her hand vibrated like a coin on a tabletop. She pressed it flat to the meat of her palm. The drilled hole stung like frostbite. The fox gave that small canid huff that, in another context, could have been laughter. Under the beam where the owl perched, a drip gathered and hung and then fell, slow as a decision, and it seemed to ring when it hit the water, a clear tone that slotted into the rest as if it had been missing until now. The hum unspooled. The animals held. Then the river moved. It did not splash or surge. It parted. Not dramatically, not in a grand gasp of parted seas, but in a careful seam that wrote itself up from deep to surface where the hydrophone line disappeared. The fog shivered and drew back from it, as if unwilling to touch the edge. Something darker than the water outlined itself, a suggestion of contours that might have been stone or might have been skin, and the air, already thick with sound, grew very still. Gleam's feathers tightened. Bracken did not blink. The seam widened the width of a hand, then two, then more. A light the colour of old glass rose through it from below, a green that had lived a long time in the dark. The river took a breath, and something vast began to rise.