The rain fell evenly like rivulets from the sky. The drops tapped on the windowsill, splashed against the leaves and made thousands of beads in the grass. Zosia was wearing yellow wellies and a blue cape with a pocket for beans, feathers and treasures. Next to her walked Fluffy, a brindle cat with a white tail tip, who pretended that every drop was a mischievous mouse. Below the block, between the trees, puddles spilled out. One was like a lake, another like a heart-shaped pond and a third as thin as a ribbon. Zosia jumped from shore to shore, made a plop-plop and listened to the water answer plim-plim. - Can, look! - She stopped suddenly. - That puddle... she blinked! Indeed, by the bench, right next to the currant bush, lay a smooth, round patch of water. In the middle something twinkled like a ladybird in the sun. Zosia crouched down. Fluffy sat up, curled his tail and murmured questioningly. At the very bottom of the puddle, as if under glass, Zosia saw a tiny door. It was as tiny as her fingernail, yet perfectly real. It had wooden planks, nails like dots and a handle as shiny as a sunflower seed. Tiny veins of gold shimmered in the door frame, like nerves in a leaf. Above the handle was a window the size of a pea. In this window flashed something blue, like the tail of a dragonfly. - Can you see it? - whispered Zosia. Fluffy blew his whiskers into the water and made a circle of waves that rippled around like bolts on a pond. Zosia tore off the thickest leaf of the babka and put it on the puddle. The leaf turned into a boat. It sailed straight over the door and.... disappeared under the surface. Zosia held her breath. After a moment, the boat floated out the other side. It had a striped pattern on it, as if someone had painted it with a rainbow of stripes. - Oho - she muttered. - This is no ordinary water. There was a snail crawling on a pebble next to her. Its shell was like wrapped candy. He was leaving a shiny thread behind him. The thread was arranged in zigzags and then in letters. Zosia squinted her eyes. The letters stuck together to form a word: "Quietly knock". Fluffy screeched quietly, as if he agreed. The rain slowed down, as if he too wanted to look. Grandma's head poked out of the third-floor window. - Sophie, just don't step on the grass! - she called out kindly. - And hold on to the bench! - All right, Grandma! - exclaimed Zosia. - We're at the bench! She sat back on her heels and leaned over the puddle. She knocked carefully with her fingernail on the water, one, two, three. The water did not splash. It trembled like a mirror. From the depths came a sound - ding! - tinkling, silver, like a bell hidden in cones. The door handle glowed with a warmer light. Through the window something blue flashed again, this time closer. It became quieter all around. The raindrops hung in the air for a moment, as if they wanted to rest. The smell of wet earth mingled with the scent of cocoa and resin, like someone opening a box of baubles on a winter evening. Zosia put her finger on the surface of the water. It wasn't wet, it didn't melt at all. It was as smooth and soft as peach skin. She touched the tiny handle. It was warm, as if someone had held it a moment before. - Mrau? - asked Fluffy, straightening her tail like an exclamation mark. - 'I think you should try it,' whispered Zosia. - Just gently. She grasped the handle with two fingers. Her cheeks were warm, her heart was beating a little faster, but not like before a storm - more like before a skip. Fluffy stood on the bench so she could see better, and laid her ears forward. - One,' said Zosia to herself. - Two. Three. The handle vibrated. The door moved slightly and the surface of the puddle stretched like a soap film. The world around dimmed, as if someone had screwed on a lamp. A light the colour of the morning sky flashed in the window. The door swung open a fingernail's width. A breeze blew from underneath, which smelled of conifers, baked bread and something else - something Zosia could not name, but which made her toes dance in her wellingtons. Beyond the door, in a miniature gap, she could see grass as tall as a finger, swaying like the sea. Across this grass, above her, colourful fish with transparent wings flew by. From afar came the ticking, but not of a clock - rather of walking buttons: tick, tick, tick. - Hello? - Zosia whispered, peeping into the window. - Is anyone there? A barely audible giggle and a quiet "ding-a-ding", like the smile of a bell, answered from inside. The door vibrated a second time, as if someone on the other side was also holding the handle. The surface of the puddle glowed and began to grow, as if someone was stretching it upwards. It made a shiny, circular tunnel. The raindrops that hung over the bench moved evenly and ran down its walls like beads on a string. Fluffy scratched the air with his paw, tried to slide his nose in, but pulled it back surprised. His nose became not dripping wet, but slightly tingling, as if he had touched moss. - 'Just a bit more,' said Zosia, feeling the bell's laughter tickle the back of her neck. - 'Hang in there, Fluffy. She gripped the handle tighter. The door fluttered like a wing. A noise came from inside, as if a sea wave had flown over the meadow. The tunnel shimmered with all the colours of a sunset. Something small and quick flashed in the window - a strip of blue, a yellow speck and a pink shadow. And then the handle moved of its own accord, as if someone on the other side had pressed it at the same time. Zosia felt a light, friendly pressure on her fingers. The door swung open a little wider still, and a warm light came from inside, in which silver grains danced. Just behind them, straight towards Zosia and Fluffy, something began to approach, which jumped like a button and left a luminous trail in the air....