Pull
The boat continued its slow movement above the wall. Long Tian didn't return to the bow; instead, he walked along the top of the wall, maintaining a pace slightly faster than the boat's, quickly scanning each shallow ditch he passed. From the seventh ditch onwards, all the ditch bottoms had the same pattern. By the eleventh ditch, the pattern was slightly deeper than the previous ones, as if it were gradually deepening in a certain direction. He called Yu Jin to his side, took the dark gray bead down again, and tested it by suspending it above the ditch—the bead sank about a finger's width deeper than it had at the seventh ditch, as if the traction force was gradually increasing.
"The pulling force is getting stronger." Long Tian retrieved the bead from his palm and handed it back to Yu Jin, "Like a directional pull, gradually converging along the wall."
He didn't stop, continuing to walk along the top of the wall. The shallow grooves along the way maintained the same arrangement, but the depth and the strength of the traction increased gradually. After passing about twenty shallow grooves, a slight curve began to appear on the wall—not a sudden turn, but an extremely gentle bend, as if the direction of the wall top, after extending in a long straight line, naturally began to deflect to the right. The angle of deflection was not large, as if it was being slowly guided to converge in a certain direction. Long Tian slowed down and observed the direction of that curve for a while, confirming that the deflection of the wall was indeed there. He squatted down next to a shallow groove, comparing the direction of the groove's bottom pattern with the direction of the wall's deflection in his mind, confirming that the two deflection directions were consistent.
He continued walking along the direction the wall had deviated from for about the time it takes to brew a cup of tea. The wall's color began to subtly change as he moved, gradually transitioning from dark gray to a lighter hue, as if the surface had been exposed to light and air for a longer period, resulting in a different frequency of surface renewal. Long Tian squatted down at the top of the wall, placing his palm on its surface—the texture was the same as before. He straightened up and walked a short distance before encountering something completely different from all the previous structures: a horizontal protrusion, about an arm's length high and the same width as the wall itself, with a smooth surface and both ends flush with the top edge, like a threshold placed horizontally on the wall.
He stopped in front of the protrusion, squatted down, and pushed it with his palm—it didn't move. He tried again with more force, but still no reaction. Yu Jin came over from behind and squatted down on the other side to examine it. There was an extremely thin seam between the protruding structure and the wall, as if it were fixed to the wall by a slot. He ran his palm along the seam and felt that the temperature at the seam was slightly lower than the surrounding stone surface. The dark gray bead also slightly deflected as it approached the surface of the protrusion, as if there was some kind of guiding structure inside it.
Long Tian stood up and walked along the raised surface, confirming that there were no obvious seams or openings. The entire protrusion spanning the top of the wall looked like a separately processed and then embedded component, cutting off the extension direction of the wall. He walked a few steps along the edge of the protrusion and squatted down in a spot on the right side, where he saw a slightly lighter-colored area. He ran his fingertip across the surface of that area and found a very thin layer of deposit. After wiping it away, he revealed a shallow engraving underneath—the shape was similar to the outline of the dark gray bead, with smooth edges, like a pre-reserved groove, and its size perfectly matched the dark gray bead.
Long Tian turned to look at Yu Jin. Yu Jin had also seen the groove. He took the dark gray bead from his collar and handed it to Long Tian. Long Tian held the bead, looked at the groove again, and then gently inserted the bead into it. The moment the bead entered the groove, a continuously moving layer of light appeared on the surface of the protrusion spanning the top of the wall, extending along the direction of the seam and covering the entire surface of the protrusion. At that moment, its surface began to light up segment by segment from bottom to top, like an oil lamp that had been steadily lit and filled with oil, starting to burn from the bottom of the wick upwards. The seam between the wall and the protrusion gradually widened within the area covered by the light layer, and the light shining through the seam illuminated the edges of the wall on both sides of the seam, illuminating the connecting surface. The protrusion, under the continuous light, moved along its... The fixed axis rose a short distance, revealing a narrow opening at the bottom. The opening was the same width as the top of the wall, narrowing inwards towards the bottom, like the top of a hidden entrance, not yet fully open. Wind from inside the opening rushed out through the increasingly wide gap, blowing onto Long Tian's face and hands, dry and warm. Long Tian squatted at the edge of the opening, probing the aura of the Origin Return Pearl along the inner wall. The aura encountered no resistance upon entering the opening, smoothly extending downwards for about ten feet before touching a hard surface, like the ground below. He withdrew his hand, sat on the raised edge, tapped the sole of his boot against the edge of the opening, then stood up, put his foot into the opening, and stepped onto the ground below. The ground was flat and stable; his entire weight didn't wobble when he landed on it. He released his hand, bent down, and passed through the opening.