In the old tenement house on Cicha Street, the rain tapped on the windowsills like fingers on a drum, and the kitchen smelled of baked apples. Grandma Hela poured tea with raspberries and smiled at Lena and Bronek. The cat Button, black with a white patch on his nose, circled under the table like a small shadow. After dinner, Grandma said: "It's time for pyjamas, teeth brushing and to bed." Lena fixed her two pigtails, Bronek pulled his red socks up to his knees, and Button hopped up on the windowsill and stared at the ceiling, as if he was listening to something people can't hear. When the lights in the flat dimmed, the corridor became long and soft with shadows. The clock ticked quietly, and from upstairs, from under the flap to the attic, came a quiet sound: dzyń.... ding... like a glass bell. The button wagged its tail. Lena and Bronek looked at each other. "Did you hear that?" whispered Lena. "Maybe it's the rain?" whispered Bronek, but his eyes lit up more than a bedside lamp. The flap to the attic was just above the shoe shelf. Lena reached for the torch, the shiny one she carried in her rucksack just in case. The button was already sitting on the cupboard, like a sentry. The second sound was clearer: a ding.... and something like a quiet knock, knock. The stairs to the attic creaked with each step. It smelled of dust, floor polish and some apples, as if the smell from the kitchen had climbed up with them. The torchlight drew yellow spots on the walls. They passed old paintings in gold frames: a gentleman with a beard and a lady in a hat. Their eyes seemed gentle, but Lena squeezed Bronk's hand tighter anyway. The attic was in semi-darkness. Thin strips of moonlight came in through a small window. In the corner stood a bicycle frame, further on two trunks with stickers in the shape of palm trees. Dust danced in the air like silver pollen. "Listen!" - said Bronek so quietly that it was almost soundless. From behind a stack of boxes came the same ding, and then the the barely audible whisper of the wind, though the window was closed. They moved a cardboard box labeled CAPS and a heavy checked suitcase. Behind them, low to the floor, shone something like a maddeningly small moon. There was a door. Tiny, maybe the size of a shoebox, made of dark wood. Leaves and a single star were carved into the frame. In the middle was a tiny brass handle. A soft light pulsed around the doorframe, as if someone was holding a lantern wrapped in a scarf behind them. Button tiptoed up (cat paws can tiptoe too) and touched the door with his nose. From inside came a quiet: knock, knock, knock. Lena felt her heart beating like a drum in a Boy Scout. On the floor beside her lay a key on a red ribbon. It was cool and smooth, with a star-shaped head, the same as the one on the frame. Bronek picked it up gently, as if it were a snail. The ribbon twitched, though no one moved it. "Maybe..." Bronek began, but did not finish. The handle of the door moved on its own, very slowly, like when the hand of a clock moves. Lena looked at the key. Suddenly it was warm in her hand, warm like a pebble lying in the sun. Ding. Knock. Knock. Knock. Button muttered a warning and crouched down, his tail turning into fluffy brush. The light around the doorframe flicked on, once brighter, once darker, like breath. "Lena..." whispered Bronek, and his voice was thinner than a thread of cobweb. "Shall we open?" Before Lena had time to answer, the key in her fingers turned itself with a soft click, and the door swung open a finger's width. A narrow strip of golden glow crawled to the floor, and from behind the crack came a sound they had never heard before....