On the fourth floor, above a bakery smelling of yeasty pastries, Nina was doing her homework. The city winked at her with neon lights and crossing signals, as if it knew the rhythm of her breathing. The notebook, bought for five zloty at the Circle, had a navy blue cover and a faded eraser. She didn't notice immediately that the paper hummed slightly as she ran her finger along the margins. The hum was reminiscent of leaves in a jar, something between a radio and completely silent rain. It started innocently enough. She wrote a shopping list: milk, pasta, butter. Underneath was a sentence she didn't remember adding: Buy lemons at Mr Frost's, he'll reduce the price today. She looked at the pen, at her handwriting, at the light of the desk lamp. The murmur was so soft that she could take it for imagination. - Do these things happen to Cuba too? - She asked on the phone. - 'To you always,' snarled Cuba, 'but lemons sound like a good deal. The next day the tram glided along the wet rails, even though no rain had been forecast for the morning. Before noon the notebook squinted with dashes and scribbled out: Don't forget your umbrella on tram 17. She didn't have an umbrella, but by 17 it was pouring so that she was coming home soaked. The pages did not soak up a drop; the letters took on a sheen as if they were made of mist. To be sure, she wrote: Who writes these prompts? The answer came after a while: I listen to what you don't hear. For a week she tested the boundaries. The notebook advised things that were small and accurate: Leave change in the vending machine, someone behind you is gone; Don't take a short cut through the car park, the paint is drying; Take your hat off, the wind will back your hair into your eyes. Several times he saved the day for her, once even a conversation with her mum by slipping her one apt word. Nina began to trust him, though she kept it a secret. The rustle of the cards got louder as she aligned them with her hand, as if the paper was breathing. On Friday evening the electricity went out. The street darkened, the bakery still smelled of hot cheese, and the phone screen whined about three per cent. The notebook swung open on its own, as if moved by a draught, and scrawled in slanted print: Don't turn on the light until you count to seven. Don't say her name. - Whose name? - she whispered. Then a soft knock sounded in the corridor, two, pause, one, like their home code. - Mrs Nino? - rang out a voice reminiscent of Majka from the third. The notebook darkened at the edges and writhed: It's not Majka. As she counted to six, the handle vibrated slightly and a single word appeared in the title line: DO NOT OPEN