Mira always chose the longest route home, the one through the old botanical park, where the cast-iron benches smelled of rain and the orangery windows shimmered like the skin of some sleeping animal. That evening the mist crept low, squeezed between the roots of the plane trees and soaked up the glow of the lanterns so warm it resembled amber. She was carrying a bag with a notepad and a stethoscope on her shoulder, a thermos wobbled by her hip. She was on call at the animal clinic - for heavy at two in the morning catching drops of silence greedily. She found him before he found her. Cinnamon, a reddish fox with black socks, stood on the wall by the gate and pretended not to notice her at all. With his tail he swept the air slowly, like a fan. When she approached, he jumped silently onto the gravel and took three steps closer, no more. From his muzzle dangled a leather strap, old and cracked, to which a copper plate was riveted. He placed it beside Mira's shoes, as if making a gift. "What have you sniffed out, king of the park paths?" - she whispered, crouching. The plate showed a stamped number, a few letters and a delicate engraving of a palm leaf. She moved her finger across it; the warmth of the metal made no sense in this cold. A short shadow fell from above and snagged the lantern. A feather - a raven with a single white feather exactly in the middle of its black wing - perched on the cracked palm of a stone botanist who had not looked at roses anymore for years, only at the empty space left by them. The feather tilted its head, as if assessing her bag for the availability of shiny objects. "Not now, thief!" - Mira grinned, though her teeth were sticking up through her lip. There was something in the air she couldn't name. Usually at this time the park was teeming with quiet life: nocturnal insects, leaves that are never motionless, even when there is no wind. Now it was like behind the glass of an aquarium where someone had briefly disconnected the pump. The noise of the bypass disappeared, even the clock on the church across the river did not chime the full hour. The silence had an edge. Cinnamon gripped the leather strap with his teeth, pulled once, a second time and then, making sure Mira was watching, turned and started down the alley. He didn't run, but walked, occasionally embracing behind him. Feather made a quiet 'krr' sound, spread his wings and soared just above a row of yew trees. Mira corrected her headlamp, picked up her plate and, without asking herself anymore, simply followed. The gentle light of the lantern ended at the conservatory. Up close, it looked like a sunken ship: the panes of glass were milky, the metal ribs were darkened by rust, and inside, despite the ban on entry, the shadows of ancient palm trees still lingered. The padlock that had held the chain for years lay in the wet grass. It wasn't cracked - it had been cut with something sharp and secure, and the edges of the cut gleamed freshly as if someone had done it five minutes ago. "It wasn't the rain that came up with it" - muttered Mira in a voice that was meant to sound confident. The grin of the cracked glass answered her with its silence. Cinnamon disappeared through the ajar sash of the door. Feather did not wait. He flew across the greenhouse aisle and plopped down on an iron beam, peering with one eye and the other. Mira drew in a breath of air. It smelled of earth evaporating from under the heat, even though it was barely a few degrees at night. It also smelled of something else: a salty note far away, like the breath of the sea applied to the ear, although it was miles to the bay from here. She moved the headlamp light around the interior. The leaves, which should have long since turned brown, remained obscenely green. A thin stream of water dripped down the railing, brilliantly, before falling into the darkness. To the right, a tangle of vines entwined around a pillar formed a pattern reminiscent of a shell spiral. Something flashed. No, it was just the eyes of a cat, which had curled up like a ball by the pot and was pretending to be asleep. Wherever she directed the light, the animals were already there: a hedgehog that had become so perfectly still that it looked like a cast-off; two pigeons, unnaturally compliant; a fat, brindle rat that was not a bit smug. They eyed her and waited. "All right," - she said, placing a copper plate on the ground as if it were an entry ticket. - "Show me what you brought me here for." Cinnamon walked around her in an arc and stopped at the very centre of the conservatory, where the ceramic tile floor formed a rosette. She knew it: the central point, the former heart of the irrigation system. As she knelt down, she felt a gentle tremor under her hand, so subtle that it might have been an illusion. She pressed her cheek against the cool glaze. The tremor was there. Uniform, like the first tone that catches the double bass in an orchestra. The feather squawked, once, draughty, and began to tap its beak on the iron beam. One, two, pause. One, two, three. Cinnamon twitched, his tail wagging like a tongue of fire. And then, from the floor - from the very centre of it - a sound answered. It wasn't loud. More of a presence than a sound, like hitting a membrane that's not on the side you're on. Mira leaned lower. "Someone there?" - sounded deafeningly before she realised it wasn't her who had spoken aloud. The sound, however it arose, formed into a rhythm in which there was something human: three short, two longer. Or maybe she just wanted to hear it that way. She sat down Turkish on the cold tiles, touching the edge of the rosette with her fingers. Up close, she saw the inscriptions covering the ceramics: worn-out variety names, numbers and dates, letters that time had licked for years. One of the numbers, as if out of spite, coincided with the one on the copper plate. She felt a weight in her stomach that was not yet anxiety, but already smelled of it. The lantern outside went out. Almost immediately it lit back up, weaker, and then went out a second time, like an eye that had been glued shut by sleep. The orangery grew darker and warmer. Steam began to paint the air with invisible brushes. Somewhere to the left a lizard rustled; the cat raised its head and did not move. The hedgehog grunted in the way hedgehogs can grunt, which is to say absurdly serious. Mira slid her fingers into the gap between the tiles. It was there, thin, as if someone had recently run a knife across the tiling. Embers blew from the depths - not fire, rather the memory of a summer that had forgotten to leave this earth. She put her ear to the floor, closed her eyes, and then heard the tapping again. This time it was answered by Feather: two short ones, a pause, one long one, almost singing. The sound from below hesitated, as if awaiting instructions, and repeated the sequence. "Don't do this to me!" - she muttered to her own heart, which began to tap out too many answers at once. Her thoughts suggested images: the old irrigation tunnels Professor Kwiecinski had told her about; the buried reservoirs, too cramped for people; the legends that you used to go down from the conservatory to the heating plant and from the heating plant to even older corridors. And the nurse's voice from reception: "Mrs Mira, you always have a nose for that." Cinnamon barked briefly, almost silently, with just a stir of his throat. His ears were high, his tail raised sharply. Without warning, he swooped down from the bar, spraying her with feather snow, and landed on the rosette, spreading his wings so that he touched her wrists with his black darts. His eyes were like black buttons with glittering depths. Mira had the impression that the raven was looking not at her, but "through" her, somewhere underneath. Somewhere behind them a drop fell. Then another. The drops settled into a rhythm - not a park-like rhythm, not a clock-like rhythm. The ground beneath the rosette vibrated harder, no longer like a double bass, but like a drum right next to the ribs. A light pulsed in the crevice into which she pressed her fingers. It was neither white nor yellow. It resembled the colour of dawn in closed eyelids, when you stand with your back to the sea and feel it getting bright before you see it. Mira pushed her hand away abruptly; the ceramic was suddenly too warm. The tiles sighed. Something beneath them moved, as if someone from below had tried to lift the lid. The lines of the joints buckled like the lines of a hand for a blink before clenching a fist. The air swelled, the animals stood still with one body, and a salty note from deep within suddenly thickened, as if to put one's lips to a shell and hear not a noise but a call. At the same moment, a long, dragging sound came from the rosette - as if the breath had trampled its way through the clay - and the edge of one of the tiles slowly began to rise. Underneath, in a narrow crevice, a strip of light lit up. Mira held her breath, Cinnamon tensed his paws, Feather clung to the ground, and what was under the floor moved once more, closer, so close that the outline could be seen through the glow....