The wind carried salt and silence as Nela Karpowicz climbed the cliff above the Baltic Sea. In front of her stood the former observatory, a concrete cylinder with a rusty dome and a glazed gallery. The door, once heavy, gave way under pressure, creaking like an old boat on the shallows. Inside, it smelled of dust, ozone and lost stories that someone had once written down and then forgotten to read. It was here that my grandfather took nightly measurements and wrote about a phenomenon he called the Whisper Line. In his diary, found years later in a toolbox, there was a sketch of the coast with mysterious marks resembling notes. Next to it, someone had annotated: "When the clocks strike thirteen, the water sings the truth". Nela, a hydrologist with a head for data and a heart for legends, decided to find out what the water really sings. She unwrapped the cables, started up the old barometers and switched on the refurbished wave recorder she had brought from Gdansk. The bars of mercury jumped above normal, although the sea seemed as calm as glass. The compass danced, unable to decide where midnight was, and the radio caught single syllables as if someone were speaking from a very deep well. Seagulls circled high and were silent, something that never happened in this place. Maks, her friend and programmer, was waiting for a video call on the other side of the Baltic map. "I'm sending a filter to clean up the noise. Also check that wall with the current map," he said when he saw the grain of the image. Nela moved the camera closer to the faded mural; the lines of the currents were arranged in a spiral that the textbooks didn't know. She touched one of the knots and felt a slight tremor, as if a hidden mechanism ran under the plaster. As she pressed harder, a stone panel sprang away at the foot of the wall, revealing a cast-iron manhole with the word 'EOL' stamped on it. The storm was coming fast, but from a different direction than usual, as if it was going parallel to the coast. Nela pushed back the hatch, hearing a muffled resonance from deep within, resembling a long, low-played chord. The staircase went down, carved into the rock and wet with salt, and tiny luminescence-like crystals glistened on the steps. "Do you have a picture there?" she asked into the microphone, but the screen flicked on and off, leaving her with her own breath and the even pulse of the waves. She picked up the torch, putting her foot on the first step, when suddenly a voice sounded again on the radio, this time clear and familiar: "Nela, don't go down alone. The line is already moving." She hesitated, turning for a moment to face the room with the mural that glistened slightly. The lines of currents were now moving as if alive, shifting nodal points, as if someone were scrolling a map through time. The clock above the door trembled and struck thirteen, although the hands stood at eleven forty-seven. At the same moment, metal clicked under her shoe, the stairs vibrated, and a shorter, sharper sound came from deep within, like a signal to go.