Tidal Period
The next day, just as dawn broke, Long Tian and Yu Jin left the city.
The morning mist hadn't yet dissipated, and there weren't many pedestrians at the city gate. The guards had changed shifts and didn't conduct a thorough check like they had the previous evening; they merely glanced at them before letting them pass. The two walked southeast along the official road. The road surface gleamed dark in the morning light, damp with dew. The wheat fields on both sides were filling out, and when the wind blew, the entire field tilted continuously in the same direction, like a piece of velvet being slowly pulled, its surface constantly changing under observation.
They crossed the high slope outside Longfish Bay in the afternoon. The sea stretched out at the bottom of the slope, the afternoon sun turning the water into a dazzling, shimmering silver. Several fishing boats were moored near the shore, their sails furled, except for a small sampan that was slowly moving on the water by a man poling it. Long Tian walked along the pier to the old man sitting at the stern mending nets and stopped in front of him. The old man looked up at him, and this time, instead of waiting for him to speak, he spoke first, "The box you brought up from underwater yesterday—you opened it."
"It's open. There's a picture inside."
The old man finished the last stitch on the net, folded it neatly, and placed it by the side of the boat. He stood up from the stern, patted the loose threads off his hands, and said, "I know that picture. It's not for everyone; it's for those who can reach that wall. You have. The path in the picture leads to a place called Great Abyss, where the entrance can only be seen during the Moon Tide of a specific month each year. This year, that Moon Tide will occur in three days."
Long Tian stood on an old wooden plank at the edge of the dock, sunlight streaming in from behind him, casting a long, slanted shadow on the deck. He listened to the old man's date and mentally compared it to the itinerary of the past few days. "How long would it take to sail from Longfish Bay to Great Abyss at normal speed?"
"At normal speed, it takes two and a half to three days. The Moon Tide window lasts about half a day, and when the tide is much lower than normal, it happens right at the estuary. As long as you reach the marked position at Great Abyss during that time, you can see the area that is usually covered underwater emerging from the water. If you catch the window but miss the optimal tide point, the entire window will be shortened." The old man secured the folded net against the gunwale, took a roll wrapped in oilcloth from an old wooden box at the stern, and handed it to the old man. "It's a tide record, showing the measured water levels in the waters near Great Abyss during the Moon Tide period each year for the past ten years."
Long Tian took the oilcloth roll, unwrapped it, and glanced inside. It contained a thick stack of coarse paper with tables drawn on it. The horizontal rows listed the year and month, while the vertical rows showed the water level and tide times. He flipped through the first two pages, then to the last, where he saw that the corresponding month and date for this year were circled in pencil, with a line of small print next to it. "Southeast wind, no heavy rain, good visibility."
He rewrapped the oilcloth roll and put it back into his leather bag, thanked the old man, but did not leave immediately. Standing by the pier, he asked the old man a few more questions about the details of the ocean currents around Great Abyss. The old man answered them one by one, his answers concise, as if he were reading a draft he had memorized for many years. After asking, Long Tian did not linger and turned to walk back along the pier. Yu Jin followed beside him, and the two walked back to the road leading inland along the slope outside Longfish Bay.
After walking about a mile, Long Tian stopped on a low slope by the roadside. He sat on the slope for about the time it takes for an incense stick to burn, combining the data from the tide record with the path marked on the silk map and going through it again. He took out the silk map from his leather bag, spread it out on his lap, and used his fingertips to trace the path on the map that was interrupted by a wavy line. He laid it out side by side in his mind with the water level change intervals marked on the tide record, and found a route and timeline that could reach the target waters before the Moon Tide window.
After confirming that everything was correct, he put the map back into his leather pouch, stood up, brushed the dirt and grass seeds off his trousers, and set off with Yu Jin back onto the road to the stone house. He had walked this road many times before, and he roughly remembered the shape of every tree along the roadside, the undulations of every section of the road, and the slope of every hill. But this time, he noticed that there were some new ruts on the road surface, wide and deep, as if left by a heavily loaded carriage. The edges of the ruts were still very clear, as if they had been made just a few days ago.
He crouched down to examine the direction of the wheel tracks—they came from the direction of the official road, turned southeast after passing the fork outside Longfish Bay. They weren't in the same direction as the direction of the Great Abyss of Moon Tide, but they weren't entirely unrelated either. He didn't linger too long by the tracks, stood up, and continued walking. Yu Jin also glanced down at the tracks, then followed him. The two continued along the same path. When they passed a low-lying area, a small section of the road was covered by shallow water, slowing their pace slightly. As they stepped through the water, the soles of their boots briefly adjusted to the new friction coefficient at the interface of water and soil before stepping back onto the dry ground. Watermarks spread out in sections behind them, some carried away by the wind, and then by the footsteps of other travelers, leaving only a thin layer of dampness on the remaining road surface, like an old cloth soaked and dried.