Reinforcing Defenses, Upgrading the Staggered Formation

After the firelight at the western lookout went out, the camp fell completely still. Chen Wuya stood at the edge of the platform, the burned metal fragment in his hand already hot from being clenched so tightly. He said nothing, merely tucked it into his sleeve and turned toward the sand table at the center of the main camp.

"Pass down the order." His voice was low, yet it pierced the night wind. "All sentries will rotate shifts early. Disrupt the rhythm of the patrol routes. No following the old rule of three steps, one halt."

His guards acknowledged the command and hurried off. He lowered his gaze to the earthen mounds heaped across the sand table—a model of the terrain surrounding the main camp. His finger swept over the eastern depression, where the drainage ditch entered. The iron fragments recovered during the day sat beside the table. The broken end of a copper tube revealed etched marks along its inner wall, almost identical to the patterns on the talisman disk he had found in the commander's signal flag.

He stared at the fracture for a moment, then suddenly grabbed a handful of fine sand and scattered it into a shallow trench at the edge of the table. Then he lifted his foot and stamped three times with different degrees of force.

The grains of sand quivered faintly.

"Just as I thought," he murmured.

Vibrations would travel along particular strata of rock, and these ditches and underground structures were natural channels for passing messages. The enemy had not withdrawn. They were hiding in the shadows, waiting for them to let down their guard.

He immediately gave the order. "Send thirty men to deepen the western slope's pit traps by another two feet. Plant short spears at the bottom, angled upward.