The Lighthouse of Words stood at the edge of Silver Bay, like a pencil stuck into the very edge of the sky. It used to guide ships to the harbour, but today it guided people to books. At the top, in a circular reading room with windows around the world, it smelled of paper, salt and Mrs Pelagia's lemon cake. That afternoon the sea was as flat as a sheet of glass, but the clouds had clear edges, as if someone had drawn them with soft chalk. Lila, eleven years old and with a leather band in her hair, was arranging small notebooks on the windowsill in which she wrote down the sounds she liked: the rustling of pages, the quiet ticking of an old clock, the dragged sound of a wave rolling back pebbles. Tymek, her older brother by a year, was constructing a tiny kite out of rubber bands and sticks, trying to see if he could fit it in his pocket without destroying the sails. Under their chair wandered Pod, a library patch cat whose tail was shaped like an exclamation mark and shook whenever something interesting happened nearby. Mrs Pelagia had gone below to get tea for the readers and cake on saucers, leaving her siblings with a wooden box that had just arrived with gifts for the library. - 'She told us not to put our fingers between the boards,' Tim reminded Tymek, knocking on the crate. It sounded like the sea in a jar. - And she tells me to always stick out new exlibrises. - Lila lifted the lid. Inside lay a pile of books dressed in stained linen covers, a handful of bookmarks cut from tickets and a bottle of thick glass, half-sunk in shavings. The bottle was corked with red wax, and inside something trembled gently, like a leaf on water. - Can you smell it? - Lila leaned over. - A sound came from somewhere. It wasn't the usual clink of glass, or the whistling of the wind. It was a single tone, thin, like a harp thread being pulled through the air. As Lila carefully tilted the bottle, the sound changed pitch, as if something inside was tuning to their movements. - In the bottle? - Tymek furrowed his brow. - 'Don't put your fingers between... OK, between the wax and the glass, better not either. Lila looked at her notebooks, then at Pod, who was staring at the bottle with wide-open eyes, like an exciting book. - I'll remember that sound,' she muttered. - 'But I think I'd rather hear it in the wild. The cork was taken up by the needle that Lila carried to take the thinnest clips out of books. She gently lifted the wax, and Tim held the bottle as if it were filled with summer and might spill. The wax slid down softly, the cork sighed, and the air in the reading room became somehow more transparent. A roll of parchment slid out from inside the bottle, old but soft. As they unrolled it, the sound grew, consisting of several notes that rolled like small waves. On the parchment, instead of ink, tiny dots and dashes shimmered, as if someone had poured silver sand and arranged it in lines, bays and trails. It was a map, but not the kind they had seen in atlases. Instead of 'north' it showed 'the place where the wind gathers courage', instead of a scale, 'Distances measured in song'. - 'I think this is a joke,' muttered Tymek, but his voice had the kind of cautious joy one has when looking through a telescope for the first time in one's life. The light coming through the great lens of the lantern refracted on the parchment and splashed across the walls. The reading room blossomed with tiny stars that were not stars, more like notes: they hovered just above their heads, perched on the spines of books and shifted as Lila repositioned the map. The clock on the wall struck the full hour - once - and for a moment all the dots trembled in unison, like a flock of sparrows taking flight. - Look - Lila touched one of the tiny inscriptions, which was seemingly just a curve of lines. The inscription formed words, slightly slanted, like the calligraphy of someone writing on a swaying deck: "North Gate: opened with light and song". - A gate to what? - Tymek tilted his head. The compass needle he always carried in his pocket flicked and instead of pointing north, it pointed to the map. - Hey! - Timothy lifted the compass closer to the parchment. The needle spun and stopped straight at the point where the line of the map made a loop. There shone a tiny star. - She... is listening. Doughnut hopped onto the windowsill, as he usually did when something sounded interesting. He sat down by the lens itself, watching the luminous dots dance on his paws. The lens sighed like a sleeping log and moved a millimetre, even though no one was turning the mechanism. The light curled into a narrow band, narrower than a ruler, and stopped on the parchment, right on the words 'Northern Gate'. - 'Don't touch it,' whispered Tymek, because there was no more he could do. Lila was already holding the map at such an angle that the light rose from the parchment, as if it were pulling itself out of the page, and hovered between them and the window. The siblings stood very straight, and their reflections in the glass looked as if they were holding their breath. The light began to thicken. It was a strange word, but that's exactly what was happening: it went from being a glow to something you could almost touch. A bright line formed in the air, right next to the windowsill, then a second, a third, until the outline of a rectangle, larger than the door to the reading room, was formed. A handle of braided light flashed on the left edge, and a subtle symbol of a wave and a star appeared on the right - identical to the one that adorned one of the higher steps leading to the lantern's outer terrace. - 'Mrs Pelagia once said that this lighthouse remembers more things than everyone in the town put together,' Lila whispered. - I think it also remembers how to open the passageways. - And I say, if we don't close this one right away...' - Tymek broke off. The bud reached out a paw and touched the bright edge. The brightness vibrated, like water when a pebble is thrown in. The cat's paw disappeared, quite, up to his wrist, and the bell on his collar sounded, not here, but as if from a place that was half a step away from the world. - Donut! - Lila froze. The cat looked at them calmly, the way cats look when they know something humans haven't noticed yet, and moved its whiskers. The other paw dipped into the glare without resistance. - Donut, come back! - Tymek leaned over but did not dare to grab the cat; the light looked soft yet ungraspable. The sound of the map accelerated. There were more notes, arranged in a short motif that Lila tried to write down in her memory, but the sounds were already changing, thickening and falling, like raindrops that know they are about to fall all at once. The lens of the lantern trembled. The books on the shelves moved, as if the air became heavier and lighter at the same time. - 'If that's the door...' - Lila said. - 'Then maybe on the other side is...' - she paused, as she remembered that not everything can be named before you walk through. - 'Maybe Mrs Pelagia should see it,' suggested Tymek, but he himself did not take his eyes off the handle of the braided light. The compass needle trembled hysterically, then stood still. It pointed not north, not south, but exactly in the centre of that bright frame. Outside, a seagull flew over and hovered for a moment in front of the window, strutting in the wind like a kite. Clouds moved behind it, but one of them, the one closest to the lighthouse, had a strange texture - it looked like an island with coves and cliffs, sculpted in vapour and shadow. For a moment, Lila was sure she saw something on that cloud that looked like a path, narrow and clear, straight to a doorway from the light. - Can you hear it? - she whispered. The music was clearly speaking to them; not in words, but in rhythm. Short, short, long. Short, long, long. As if someone was tapping out an invitation with their fingers on the table top. The bud slid deeper. Its patched fur disappeared, then its belly, until all that was left was its tail - exclamation and question mark at once - and a bell that now sounded from two sides: here and far away. The glow dimmed slightly, like a candle flame when the window glass lets less wind through. - 'If we don't go in now, maybe it will close,' Lila said, and in the sound of her voice Timothy heard the same thing he sometimes heard when his sister did something for the first time and knew he would remember that moment for a lifetime. - 'And if we go in...' - Tymek looked at the map. The silver dots swirled and arranged themselves into shapes he couldn't name, but he understood them as one understands the direction of the wind before even asking the compass. - ...then we will have to remember the way back. - That's what maps are for - Lila squeezed the roll in her hand. - And singing. The air thickened once more. The movement of Tymek's jacket outlined a shadow in the glow, which on the other side lit up like an upturned mirror. The handle looked warm, though it was made of pure light. The sound of the map reached its highest note and hovered, waiting. Lila and Tim looked into each other's eyes, and then, as sometimes happens between siblings who grew up in a place where books can shine and cats have the courage of the first step, they simultaneously reached out their hands. Their fingers touched the light handle. At the same instant, the lens of the lantern flashed as if someone had blinked an entire sea. The glow in the door moved deeper, showing for a split second the outline of something that was neither a room nor a courtyard nor a mere sky. The doughnut bell sounded louder, and the note from the map fell silent for a moment - as if someone on the other side had also put their hand on the doorknob.