The foggy season in Kirishima comes earlier than in previous years, and the thick water vapor is like insoluble ink, tightly covering the lighthouse standing on the cliff. Lin Yan has been guarding this century-old lighthouse for two years. His daily work is nothing more than checking the wick at sunrise and lighting the beam at sunset. He spends the silent time accompanied by the sound of waves and fog horns, until the first anonymous letter is stuffed into the crack of the lighthouse door.
The envelope was unsigned, and the handwriting was slightly blurred by water. It only contained one sentence: "The fog three years ago was as thick as now. The bones of the ship were hidden in the places where the lighthouse did not shine." This sentence was like a needle, piercing the calm that Lin Yan deliberately maintained - the case of the missing fishing boat that made him resign three years ago is still an unsolved case. The missing captain was the only person willing to provide clues when he was trying to restore the truth.
After that, anonymous letters appeared one after another, each with the damp atmosphere of Kirishima, and the content gradually became more specific from vague hints: pointing to the dusty old diary on the bottom of the lighthouse, the unnoticeable scratches on the cliff, and even the notebook he hid under the bed recording the details of the investigation. At the same time, strange things happened one after another in the fog - the lighthouse that was supposed to light up on time suddenly went out for half an hour, wooden boards with old navigation marks drifted from the seaside, and the vague sound of ships could always be heard in the fog late at night.
