Szymek lived by the lighthouse, where the street ends. After yesterday's storm, the sea had thrown the map bottle ashore. The ink on the map floated like a shoal, twisting and shimmering. The wind rose winked at him with a red dot, like an eye. In the margin someone had written briefly: 'Only after dusk'. As it turned grey, the boy slipped the map under his jacket and set off. The lighthouse was usually closed by Mr Rybak, but today the door was ajar. Basil, the lighthouse keeper's cat, dashed up the stairs and looked at Szymek. "Meow," he said meaningfully, and pointed down the dark corridor with his tail. The map trembled in the boy's hand and lit up the stone floor. The lines shifted and formed an arrow towards the basement. They walked down together, hearing a quiet clanging below, like an underwater bell. The walls were damp and salty, smelling of iodine and rust. Wet letters appeared on the wall, assembled from drops of water. They formed the word "Entrance" and then added: "Don't look back." Szymek swallowed his saliva. "I'm coming, but only a piece," he whispered. Basil screeched and disappeared first into the black stairwell. At the end of the tunnel, a round door with a small porthole waited. The porthole looked like a fish's eye, full of moving silver clouds. The boy touched the metal. It was warm, like the hand of another person. Then the map lit up with a golden thread and vibrated in his pocket. Behind the door, something sighed and said his name clearly. The bolt lifted of its own accord and the porthole began to open slowly....