The stone of the Arcade Courtyard that night breathed like someone who had been holding their breath for a long time. Drizzle stroked the cloisters and the yellow streak of the lamp reflected in the wet flags of the cobbles. In the silence, all that could be heard were distant footsteps and individual drops falling from the gutter onto the brass grating of the drain. Karolina Borkowska pressed the heavy door of the Manuscript Cabinet with her hip. The small bells in the handle chimed, as if an old chest of silver had moved in a dream. Inside there was a familiar, soothing chill and the smell of leather, lamp soot and paper that had lain for centuries. Waiting on the tabletop were sable bristle brushes, a wooden cube for smoothing parchment, cranberry gum arabica in a jar and a new, long copy of a book wrapped in conservation cloth, sealed with the lacquer seal of the university. The seal depicted a bird with a too-long tail and a too-penetrating eye. It was not associated with anything Karolina had seen in heraldry. Beneath the wax wove a note: Find from the wall, room under the clock, please make a preliminary assessment by the morning. The conservator's initials in the corner looked like a slight sleight of hand. - Long today, Mrs Karolina? - asked Victor, a doorkeeper with a beard as hard as a shoe brush. He leaned in the doorframe and jingled a bunch of keys in which there was not a single one like the others. - I'll just have a look and describe. - She smiled without conviction. - Can I borrow a knife? Victor tugged at his pocket, pulled out an eyeglass case and, to her amazement, handed over a black blade with a barely visible sheen. - It's not made of metal. Obsidian. Grandfather said it cuts better than steel, and remembers more than a man. Just be careful with it. - He nodded towards the corridor. - I'll close the gate at one o'clock. If anything happens, call out. When his footsteps quieted, Carol cut the wax in one smooth movement. The canvas swung open reluctantly, like a wet curtain. She looked at the back of the book and understood what had so disturbed the conservator: the binding was made of leather that was neither calf nor goat. It shimmered with a quiet, pearly sheen and bore a network of tiny scars - as if from sand. She could almost smell the salty air and the distant rumbling of the waves against the wooden side. - A flatfish? - She muttered to herself. - Or something older. The ironic thought flashed through her that a library in the middle of a continent sometimes smelled more like a port than a scriptorium. She put on her cotton gloves, slipped her spatula under the cloven edge and opened the book as gently as if she were waking a sleeping animal. The first page was blank, only in the corner was a tiny mark like a pupil - a circle with a line that was not a line but the shadow of a pen. Further on, the letters were arranged in thick columns of an unfamiliar typeface. It was not Latin or Old French, although she picked out familiar shapes in places: 'sal', 'axis', 'nox'. The ink was not completely dry; it seemed soft, like living tissue. When she tilted the lamp, the black ribbons breathed deeply, in the rhythm of a distant heartbeat. She lifted her gaze to the wall. Above her table hung a heavy replica of an astrolabe, the legacy of the previous head of the Cabinet. The iron was worn at the edges and the zodiac signs had, as always, some of the artist's humour: Scorpio resembled a smiling river, and Sagittarius crouched like a bird on one leg. Carolina was always amused by the slight perversity inherent in the seriousness of the instrument. Suddenly, something clicked quietly behind the wall, like a chain being pulled too fast. The clock in the hall below the clock room - the one that usually went like a tired clerk - sped up half a beat. Carolina tensed her back, listened. The drops outside, the clock, her own breathing. And then something else - a quiet, barely audible tone in deep A, like a bee-barrel in the corner of the room. She moved her finger across the vein of ink. The text murmured quietly and swung under her fingertip, revealing a drawing: a plan of the courtyard, but not as she had just seen it. Black flames marked the corners, a star with seven arms in the portico, and a tiny oculus with a ring of tiny symbols where she stood. All signed with abbreviations and signs that suddenly made sense, as if they were waiting for the right angle of light to fall on them. "When the spell of Night stands by the King's spit, tilt the eyelid of the city." - she read the rubric in the corner of the drawing in a whisper. She did not know the name of such a constellation, but the sky on the astrolabe was drawn as she had seen it over Krakow in winter, and today the clouds had moved away for a moment, showing a pin-sharp star by the bell tower. She extinguished the lamp, leaving only a small torch of cold light, and looked up. She remembered the professor's words: "Instruments don't lie, but we sometimes don't ask them questions in the right language." She grasped the lower ring of the astrolabe and moved it until the odd name from the rubric - the King's Spit, whatever it was - began to arrange itself in proper relation to the rest. At the same instant, the oculus on the page of the book trembled and began to dilate like a pupil in the darkness. A luminous circle appeared on the edge of the table, opening a golden gap between the boards and the air. It smelled of damp stone and juniper. Carol wasn't in the habit of following the voice of strange smells and luminous circles, but it trembled in her fingers the same way it had trembled when she first touched a real illumination in the shadows when she was twenty. She leaned over, slid her hand under the desk and felt something like a rail on the stone floor. A peg protruded from under one slab. She pulled. The weight surprised her: the stone gave way without a rasp, as if the hinges had been greased by someone who likes silence. A piece of the floor turned and lifted, revealing a narrow gap and a staircase running down, damp but slick, as if she had walked on it for years. The torchlight glided across the wall, painting powdered salt patterns and rows of tiny incisions: calendars that someone had scratched with their days in a hundred different eras. From above, the soft hum of the city could be heard, from below, a silence so thick you could feel it on your tongue. - Victor? - she called out. The echo picked up his name and laid it on the steps, returning slowed as if it had passed through sticky water. She descended carefully, counting the steps. At the twelfth step she felt the pure coldness of metal under her fingers. The door. Their surface was porous, covered in relief resembling a map of rivers, but when she touched it, the lines flowed, forming letters she knew from the cards. She slid the obsidian blade into the narrow opening and twisted. The mechanism responded with a deafening sigh. The chamber was larger than the courtyard above allowed her to believe. At first she thought it strange, for she should have gone under the fountain after all, but there was no fountain here. There was a circle of black stone on which rested a flat bowl of water, so smooth that it reflected the ceiling like polished glass. Around it, on hooks, hung upside-down hourglasses; the sand did not fall, but slowly rose upwards, as if it wanted to go back from whence it came. Against the wall stood a desk, on it a small metal casket and a ring of dark silver in which a tiny amber was trapped. In the amber hung a thread of air, as thin as a hair and so black that it seemed not to reflect light. Karolina touched the ring and felt an unsettling, familiar tremor in her wrist, like when her grandmother had once given her old jewellery to try on, which had never belonged to them alone. The torch went out. A moment later it lit up on its own, weaker. As if something had covered and exposed her eye. - 'Lina,' said someone softly, from places that had no mouth. She couldn't remember the last time someone had called her that. Only her grandmother had the right to shorten her name to this form and she did it in a whisper, as if uttering an incantation. Carol reflexively put her hand to her chest, where she wore a thin chain under her shirt. She had not worn it today; she had left it on her nightstand. Yet for a second she felt the cool touch of metal on her skin. The clock in the corridor struck once. Then, without waiting, it struck a second and a third, too soon. Karolina's phone showed 23:06, yet the heart of the chamber was counting down something else. A point of light appeared on the surface of the water, so tiny that she could take it for the reflection of a speck of dust. The point grew into a short line, and the line into a circle, consistent in diameter with the ring on her fingers, which she did not remember trembling so restlessly. - Who's there? - she asked. The voice sounded too loud and uncertain, as in a new, empty flat. The water responded with a quiet suction, almost imperceptible. After a moment, the surface rose like a membrane. Shapes shimmered underneath - not sharp, not unmistakable - the shadows of tables, the backs of chairs, the outline of a window where the wind never reached. And a face. First a face, but then immediately another, delayed, like an echo in a mirror. One looked straight ahead, the other a little below, as if unsure whether it was slow. - Lina - the voice repeated. More clearly this time. A shudder started in her shoulder blades and travelled to the tips of her toes. She thought for a second about how she should call Viktor. That she should close the door and write everything down, calmly, on millimetre paper like before. The other part of her - the part that caught the train at the last minute and never learned to park upright - took a step forward. The edge of the black circle was dry, despite the dampness in the air. She touched it with her hand. It was warm. The water stretched and bulged in the centre, forming a convex lens. Up close, she saw someone lift a hand in that space. Her fingernails were darkened and drenched in ink, like those of someone who spends all day rinsing letters from a grain of parchment. On her finger shone a ring of dark silver. The same as the one Karolina now held, unconsciously, in her left hand. - 'Don't touch it,' said Victor's voice from above. It was thin, distant, like carrying a pipe. - Mrs Karolina, please come back! The cry went up her spine, but at the same instant, out of the water, someone moved a ring and slid it along the raised surface. It left behind a streak of light, thin, sharp and cold like an obsidian blade. The streak touched the tips of Caroline's fingers. The stone beneath her feet twitched, as if something very old had been knocked over, and the clock above them began to go back one beat.