On a shelf beneath a translucent map of sea currents lay a brass compass that shouldn't work. Lena, a cartographer from the harbour workshop, turned it in her fingers and watched the needle make small, nervous loops. The compass had been brought to her by the postman today, wrapped in paper with the seal of a non-existent lighthouse. Inside was just a piece of paper with a command: "Check the cliff behind the Falcon" and a signature: Nobody. Lena collected things that argued with the map, because they were the only things that opened up new paths. Marek from the library looked at the map and just shrugged his shoulders. "It's a joke, right?" Lena shrugged her head: "The water clocks the silence between low tide and high tide." Marek knew the paths under the cliff because he collected plastic from the beach every week. The old chronicles mentioned a bay that disappeared with every nineteenth full moon. When it returned, it was said to give back lost boats and pick up new captains. They arranged for dusk, when the tide receded lazily and the seagulls fell asleep on the red buoys. The evening smelled of iodine and wet wood, and the sky was the colour of old maps. The compass needle trembled as if responding to a deep breath of stone. Beyond the Falcon, a lone bird-shaped rock, they found a narrow gully draped in broken juniper. The air was panting with invisible insects, and the sea mist tasted like salt and ash. Deep in the gully was a flat boulder with an engraved word: LISTEN. They stopped and listened, suppressing their breath as if they might scar the silence. The waves stopped rustling, as if someone had turned the sea for a moment. A gurgling rumble came from the black crevice, rhythmic, almost clock-like. "The water clock" - Lena whispered. They stuck their arms into the cold crevice and squeezed inside, rubbing their jackets against the damp slate. For a moment they had the impression that they were standing at the heart of a cliff that was beating very slowly. The cave was not wild, which struck them more than the chill on their skin. Someone had once built it up with a platform of bales and ropes, and rusty lanterns hung from hooks. The sound grew until they felt it underfoot, like the sweep of an invisible pendulum. Eventually they came to a circular chamber where a large, half-buried bronze disk lay on the stone floor. The disk was marked with stars and letters, and in the middle was a lock in the shape of a trident. The letters were arranged in an alphabet that Lena did not know, but she could feel their direction like the direction of the wind. There were tiny indentations between the stars, as if someone had marked undiscovered trails. Lena associated it with a small tin attached to a compass chain. She lifted the plate and felt the metal tremble gently under her fingers. At the same moment, the disk rustled, as if responding. The water level behind the platform suddenly dropped, revealing a dark staircase. Marek took a breath, but an unfamiliar torchlight flashed from the corridor behind them. Someone stood in the crevice, unmoving, and said only one, all too calm phrase: "Put it down, Lena." "You have no idea what you'll wake up." The voice sounded familiar, but no name wanted to come to Lena's mind.