Grandmother lived in a tenement on Flower Street, in the very attic. It smelled of baked apple, turmeric and fresh linen. That afternoon, the rain drummed against the window and two small coats hung on the doorknob: a yellow one with dots and a navy blue one with stars. - 'Grandma, can we draw on the floor? - asked Lila, who was seven years old, with a long fringe and pockets full of buttons. - 'Only with chalk, darling, and only in the corridor,' smiled Granny and set a cup of cocoa on the table. - 'And when you're done, we'll clean up together. Kostek, Lila's younger brother, was five years old and wore striped socks. He was already pulling out a box of coloured chalk. The corridor at Grandma's was as long as a train and as quiet as the moon in the evening. - We'll make a big door! - Lila said. - The kind to another place. With a handle, hinges and a keyhole. - And on the other side there will be kites - added Kostek. - And grass that sings. Lila began to draw. First a rectangle, then an arch at the top, decorative leaves on the sides. Kostek carefully added a round handle and a small round hole just below it. The lines were thick, soft and slightly crumbling, leaving a dusting of colour. - 'It would be good to have a key,' muttered Lila, putting a finger to her chin. - 'Maybe it's in Grandma's vault? - whispered Kostek. They called the treasury a small cupboard where Grandma kept strange treasures: ribbons, buttons, candy boxes and wooden clothespins. Lila carefully opened the door. Inside, at the very end, she found a tin box with a painted cat and a moon. - May I? - she called out into the kitchen. - Have a look, just don't crumble anything! - replied Grandma, stirring the pot with a spoon. - There are a lot of old trinkets in there. Lila lifted the lid and the crayon cubes clattered against the wood. In the box lay a small silver key. On its head someone had carved a cloud. - It fit! - Delighted, Kostek jumped up so that his socks slipped an inch. When the key touched the drawn hole, something very quiet happened. It was as if a laugh had rustled under the boards. The handle, drawn in thick yellow chalk, suddenly became cool, like real metal. - Can you feel it? - Lila put her fingers on it. - She is hard. Kostek put his ear to the door. - There... something is humming. Like the wind with kites. The whole corridor fell silent. The rain was still tapping, but as if further away, behind a thick curtain. The clock on the wall ticked slowly and looked at the children with a round, wise eye. When Lila slid the key in, the chalky keyhole flashed a silver spark. "Click." - Lila, and how is it dark in there? - Kostek asked in a whisper. - We'll have a look first," whispered Lila. - Like in the wardrobe when we play hide and seek. Grandma, passing by with a sheet of apple cake, crouched by the chalk door. She looked at the key, then at the children. She smiled as if she already knew a great many drawing stories. - 'Remember, take jumpers,' she said simply, as if she were advising an autumn outing. - And don't talk to the first wind. - You don't talk to the wind first, you talk to the wind second - joked Kostek and all three laughed. Grandma returned to the kitchen and Lila carefully turned the key. The lock clicked, but not like a normal lock. The floor trembled and the chalk lines twitched, as if taking on water and light. The handle flashed. For a moment, the whole corridor smelled of sea and cinnamon. - Do you hear those bells? - Kostek asked, grabbing Lila by the sleeve. Somewhere, very far away, three sonorous notes buzzed, like little silver fish. Through the thin gap between the door and the floor, a unique light began to come in. It was not white or yellow. It was like a morning mist with sparks dancing in it. Kostek crouched down and looked under the door itself. - There are... steps? - Soft white steps, as if arranged from clouds, were reflected in his eyes. Lila felt her heart beat faster, but not from fear, but from curiosity tickling her stomach. She carefully placed her hand on the doorknob. It was as warm as a cup of cocoa. - Just a bit more,' she whispered. - Just a little. The door swung open about a hand's width. The corridor got bigger, as if it had more room to breathe. A soft breeze blew in from the other side, smelling of the dust of old books, wet grass and something that resembled baked apples, but sweeter. - Look! - Kostek pointed his finger at something that flashed just inside the threshold. A feather had fallen out from inside. It wasn't like an ordinary feather. It had thin golden edges and was warm when Lila touched it with her fingertip. - It glows - she whispered. - But only in the middle. The feather fluttered, as if ashamed to be so close to the floor, and rose higher, up to eye level. It danced a little circle-dance and flew back, into the gap. Then something murmured inside, like the laughter of a lost stream. Then there was a quiet sound: knock, knock, knock - three times, very politely. - Who is knocking on our drawn door? - asked Kostek, jumping up and down with excitement. The door answered with just a slight twitch. The handle moved of its own accord, as if someone on the other side also had a hand in it. Outside, the rain fell silent, as if the whole world had stopped for a moment. - Are you ready? - came Grandma's voice from the kitchen. It was calm, yet full of something that always made Lila feel braver. - 'A little,' Lila said, but her voice escaped into a whisper. She took her star-spangled jumper off the chair and put it on quickly. Kostek pulled the hood from his sweatshirt so that he looked like a soft frog. They stood together by the door, close, so close that Lila could feel the warmth of her brother's hand. - 'Let's count to three,' Kostek suggested. - 'You count and I'll hold the handle. - Once... - Lila took a breath and smelled a smell she didn't know, which was like the promise of a holiday. - Two... - The corridor seemed to brighten and the chalk lines around the door shimmered like stardust. - Three! - they said together. The handle turned all the way with a quiet 'click'. The door swung open wider. On that side flashed soft steps of clouds, distant, colourful kites and something that looked like a wooden lantern suspended in the air. And then, in the exact moment that could not be stopped, a voice, warm and startled, flowed to them from within: - Lila? Kostek? The children looked at each other the way one looks when a brand new Saturday opens. And the doorknob in their hands suddenly became even warmer, as if someone on the other side had started to open the door wide....