Chapter 89: Luring the Enemy

The valley floor was largely composed of sand and gravel, smoothed by the wash of the waters—a natural corridor. Marching on such terrain, close to the water source, had always been the preferred route; the Tibetans chose it, and the Tang pursuers followed suit. Yang Yu’s body moved in rhythm with his horse’s hoofbeats, rising and falling slightly. He did not sit fully in the saddle, leaving about two fingers’ width of space; he relied on his feet, braced in the stirrups, to maintain balance. Every so often, he would settle into the saddle for a moment, allowing himself a brief respite.

Cavalrymen needed stamina; without it, the jarring motion alone would be unbearable. As the vanguard, he and the fifty riders behind him each had two horses. Their spare mounts were not entirely unburdened, laden with weapons, supplies, and equipment. Heavy cavalry for breaking formations, light cavalry for pursuit—all depended on horse power. Without rotation, a single horse would be spent in a matter of hours, a cost even the mighty Tang Empire could not afford.

Thus, the fifty riders and their hundred horses moved at a steady pace across the sandy valley floor, with Yang Yu at the front, eyes fixed ahead, following the Tibetan tracks. He gauged the distance to his quarry, estimating how far ahead they might be.

The final military council had, in the end, heeded Liu Ji’s advice. For safety’s sake, General Feng Changqing dispatched all his light cavalry. The main force was Yang He’s Yutian troops—about two thousand men. Liang Zai’s garrison at Bohuan Fortress contributed nearly five hundred light cavalry, and even the commander’s own elite guards were nearly sent, had Duan Xiushi and others not firmly objected.

Such a thing could not be allowed. If disaster struck, those guards were their only hope of escape. In Hengluosi, it was these very guards who ensured Gao Xianzhi and others did not fall into Arab hands.

As for the commander, Yang He’s age relegated the duty to Liang Zai. Tian Zhen’s unit, having earned merit crossing the river, would not compete for the honor. Among them, none was more suited to leading the vanguard than Yang Yu.

He had already traversed this route before; any Tibetan tricks would be caught at a few key points, the fruit of intelligence he and Liu Ji had risked their lives to obtain.

Though it appeared a full-speed pursuit, Yang Yu paced himself. He kept the horses at a moderate speed—quick enough, but easily halted if needed. As the pace-setter, the entire squad followed his lead.

“Whoa!”

Drawing near another ambush spot, he called out, gently pulling the reins to slow his mount, signaling for the squad to proceed cautiously. Instantly, the cavalry formed a semicircular defensive formation around him, ready for any surprise attack.

“Thirty paces ahead—go check for an ambush.”

Yang Yu pointed forward and gave orders. Two cavalrymen rode out in response, one ahead of the other, spaced five paces apart—a standard scouting formation. If the front scout was attacked, the rear would be shielded by his body, gaining a chance to escape.

The area ahead was a hollow in the mountain. The slopes here were steep, with few places large enough to hide a sizable force. Yang Yu had already memorized these spots on his return journey. His gaze did not follow the scouts, but instead scanned the ground.

The sandy riverbed easily bore traces. A skilled scout could judge the enemy’s passage by the depth and freshness of prints. Though not expert, Yang Yu could tell at a glance the Tibetans had not passed long ago.

This was highly unusual. When the Tibetans retreated, their iron chain bridge was not yet built—it took two hours to construct, and with so many men and horses crowding a bridge barely two paces wide, crossing would be slow, another hour at least. Three hours’ difference amounted to most of a daylight period. How, then, were the Tibetans still so close?

Unless they were luring the enemy!

Yang Yu began to understand Liu Ji’s earlier assessment: the enemy had never intended to hold Poyi River at all. The battle there was only to give the Tang a false impression of a last stand.

Unease stirred within him. He turned to a subordinate, asking, “How far behind is the rear?”

“It was said to be five li.”

“Tell Old Ma, the gap must not exceed three li. The rear force as well—if there’s no support in emergencies, let him take up the vanguard role.”

His subordinate spun his horse without hesitation. Their squad had pushed too far ahead; the supporting force, led by Ma Lin—commander of the central army, governor of Diezhou, and officer of the Right Jinwu Guard—was five li behind. Yang Yu’s concerns were unsurprising.

Soon, the scouts returned: no ambush.

Yang Yu signaled to advance. The fifty cavalrymen did not crowd forward, but formed a long column. The dense, urgent hoofbeats echoed through the valley, sending birds fleeing in all directions.

In truth, Xidongzan was just ahead, less than half an hour’s ride away. Leading the Tibetan cavalry, he was preceded by a chaotic mass of routed troops—once three thousand strong, mostly local light infantry. They had left over seven hundred corpses on the riverbank, with about fifteen or sixteen hundred survivors now fleeing for their lives. Many of the tracks Yang Yu saw in the valley belonged to these fugitives.

Xidongzan did not immediately gather them up, wanting to give the Tang pursuers the illusion of easy prey. Chasing a routed enemy promised great results for little cost; the Tang had no reason to refuse.

Indeed, the Tang did not hold back. The pursuers followed almost immediately after the Tibetans crossed the bridge. From the time Xidongzan began withdrawing, more than an hour passed before the Tang closed to within half an hour’s distance, about to enter the Skar River Valley from the Indus Valley. Yet Xidongzan felt little satisfaction.

The reason was simple: these Tang soldiers were far too cautious, checking every possible hiding place. This meant they knew the terrain well, reminding Xidongzan of the two scouts who escaped from Hepulao Fortress.

One mistake, and disaster multiplies.

A squad of fifty, spread out over several hundred paces—even if ambushed, few would be lost. Did the Tang always operate this way, or had they sensed something? Xidongzan looked at the confluence of two rivers, a triangular expanse, and hesitated.

He longed for a battle to lift his men’s spirits, to show them that these Tang soldiers were no different from those decades ago at Dafei River, Jishi Mountain, and the borders of Qinghai. But to do so, he had to annihilate them, leaving no survivors to betray his intentions—not merely startle them.

The Tang had indeed posed a dilemma. They knew neither how many followed the fifty, nor their distance. Could the enemy themselves be bait?

After much deliberation, Xidongzan abandoned the idea. The terrain here was a narrow corridor—river on one side, cliffs on the other, no space for envelopment. It was ideal for a blocking action, but such attrition was not the way of the wise.

Only one place remained: Hepulao Fortress.