In the evening, as the storm rattled the aerials over the city, Lena sat in the city archive under the former fort. The fluorescent lights buzzed steadily and boxes of residents' gifts smelled of dust and lavender from the drawers. From the last box she pulled out a roll of map on parchment, bound with a leather strap and signed with today's date. The town on the map was familiar, but it was punctuated by canals she had never seen and a Square of Silence she had never seen. - Another cartographer's fantasy? - muttered Bartek, the night watchman, leaning against a bookcase and sipping tea from a thermos. - 'Look at the wind rose,' said Lena. - It fits the mosaic on the floor like a key to a lock. They laid the map on the polished stones where the pre-war masons had arranged a circle with a brass compass in the middle. The parchment stretched softly, and a needle drawn near the northern edge indicated not their world but a corridor. A drop fell from the ceiling; the sky leaked somewhere far away, and here it smelled of wet brick and old grease. Lena moved the map a millimetre to the right, aligned the line of the channel with a crack in the stone and held her breath. The mosaic beneath the rose twitched, as if a shoal had swum beneath it, and the steel balustrade grew colder at the touch. A dull light spilled across the map where the outline of the door had been, reflecting nothing but its own depth. - Can you hear? - Bartek tilted his head, like a dog listening, though the clocks in the archive had stood for years. In the silence a ticking developed, at first infrequent, then even, as if someone was winding a spring under the floor. Lena tied a measuring cord around her wrist, gave the other end to Bartek, and touched the luminous edge with a metal ruler. The surface sunk by a hair and trembled; the ruler heated up, and the reflection of the stairs down appeared in the light. On the first step stood a figure in a cloak of tied ticket tapes, holding a bag stitched together from cut-up maps. Her face was obscured by a hood, but she raised her hand, displaying a brass key shaped like a wind rose. The world on the other side was the same, and yet not this one: Lena could see lanterns on the water and seagulls waving soundlessly. Bartek squeezed the string, the controls on the monitors blinked, as if the image had receded and then dissolved into pixels. - Who's that? - he whispered. The figure touched the edge of the portal and swung it open like a curtain; something small sounded on the stones, and the map itself added a new channel bed. Lena bent down to pick up the object, but the surface pushed her hand away and she felt a cool grip from inside. Slow footsteps came from the corridor behind the steel door, as if someone was counting them out loud, and the staircase light dimmed in the portal. - Leno, don't move! - shouted Bartek, but the cord tightened as something gently pulled her into the depths.