Hsuang accepted the sack. Noting that every peng in the Twenty-Five Armies was watching him, he turned the bag over. The head of a Shou soldier tumbled out. Though Hsuang could not be sure, he assumed the head belonged to one of his scouts.

Aware that any sign of disgust or repulsion would translate into low morale, the lord calmly retrieved the grisly head and returned it to the sack. Before he could think of any encouraging words, however, the ground began to tremble. A distant rumble came from the other side of the valley, and Hsuang's heart suddenly beat harder.

"The barbarians are coming," Cheng said, his mouth open in astonishment. "They intend to fight a night battle!"

Dropping the sack, Hsuang ordered, "Stand ready!"

The order was unnecessary. Like their commander, all forty-five thousand of his soldiers had focused their attention on the field. The dim light and heavy smoke made it impossible to see in any detail what was happening on the opposite side of the valley. To Hsuang, it seemed as though the far hill had come alive and was rolling toward them. His feet began to tingle, and the rumble grew increasingly thunderous. Two hundred yards in front of the first barricade, a teeming mass of galloping horses became visible in the smoldering barley fields.

Hsuang nodded to the noble commanding the rocketeers. "Fire when ready," he said to the nan.

The noble lifted his arm to signal, then looked twenty feet down the slope to where his standard-bearer stood. The nan did not give the order to fire, however. Though his rockets were more powerful than normal arrows, they were less accurate and had a shorter range.

The barbarians emerged from the smoke completely, riding shoulder to shoulder. They had let their reins fall free and were using both hands to nock arrows in their bows. In the deepening twilight, the riders' bulky silhouettes made them look like no more than shadows. Their line stretched for an entire mile down the valley, and Hsuang thought he could see several more ranks emerging from the smoke. At a minimum, the charge numbered sixty thousand men.

Eyeing the approaching wall of horsemen, Cheng said, "The enemy has committed his entire army. We'll destroy them in a single battle!"

"What makes you think this is the Tuigan's entire army?" Hsuang asked. His eyes remained fixed on the valley below.

Cheng did not answer. Like Hsuang and the others, he was waiting for the rockets to fire. The rocketeers stood behind the far barricade, separated from the closest conventional troops by gaps of twenty or thirty yards. Each man's kettle held thirty arrows and sat braced atop the barricade. The small end of each kettle was packed with thunder-powder. When the wick was lit, the powder would ignite, shooting the arrows out with incredible force. Or at least that was the theory.

When the barbarians approached to within seventy-five yards of the first barricade, their entire line suddenly reined their horses to a halt.

"What are they doing?" Hsuang demanded, angrily pointing at the enemy. "Why stop a charge in midstride?"

No one could answer.

The air resonated with the twang of sixty thousand Tuigan bowstrings. A black swarm of arrows sailed toward the first barricade. All along the line, men screamed in agony and fell. Hundreds of motionless Shou slipped into the brook and began to drift downstream.

"We cannot wait for the rocketeers any longer!" Hsuang snapped, chastising himself for allowing the barbarians to strike the first blow.

"They're barely within range," the nan objected, still holding his signal arm aloft. "If we wait just a little longer—"

"They're as close as they're going to come," Hsuang yelled, pointing at the stationary line. "Give the order!"

Frowning, the noble looked toward his standard-bearer and dropped his arm. An instant later, the turtle and shark crest began swaying from side to side.

The rocketeers touched their torches to the wicks. A series of booms and claps echoed through the valley, and great billows of black smoke rose into the air.

Hsuang could barely believe the results. In ten places, the kettles exploded instantly, flinging chunks of log and stray arrows in all directions. The rocketeers simply disappeared with the rest of the debris, and all that remained where they had stood were gaping holes in the barricade.

When the kettles did not explode, they sprayed their arrows out in an erratic, cone-shaped pattern that usually fell far short of the barbarian lines. The rockets that did reach the enemy, however, were effective. Nearly twenty riders sprouted arrows and flew out of their saddles with such force that there could be no doubt the men's armor had been penetrated. Dozens of horses dropped to the ground and did not move, dead at first impact. Hsuang could see why his subordinate had wanted to wait. At close range, the rockets' impact would have been devastating.

The effect on the Tuigan horses was more impressive than the number of casualties, however. Horrified whinnies and terrified neighs filled the valley. Thousands of mounts threw their riders, and hundreds of riders died beneath their beasts' frightened hooves. Many of the barbarians thrust their bows into their holsters, and used both hands to grab for their reins in a futile attempt to control their mounts. Only a few of the horsewarriors could keep their thoughts on the Shou.

Without looking away from the battle, Hsuang said, "Have the archers open fire."

His aide relayed the message to the appropriate standard-bearers. An instant later, the distinctive bass snaps of ten-thousand bows vibrated up the hill. A flock of shafts sailed over the brook and struck the wall of horsemen. Thousands of riders fell, and more panic spread through the lines as wounded and terrified horses turned to flee.

"Shall I fire the catapults?" Tzu Cheng asked eagerly. "A few more explosions will route the enemy."

"No," Hsuang replied, lifting a restraining hand.

As of yet, the enemy had not regained control of their horses. He saw no use in chasing them away before the archers could take full advantage of the barbarian disarray.

Another flight of arrows struck the enemy line. Several thousand riders fell, but Hsuang could see the horsewarriors calming their mounts. Loud noises might disturb Tuigan horses, but the beasts were accustomed to men dying upon their backs.

The archers fired another volley, killing even more barbarians than they had with the first two. Hsuang nodded to Cheng. "Loose your thunder bombs," he said.

Tzu Cheng relayed the message to his adjutant, and a moment later his standard waved. The artillerists touched their torches to the wicks of the small iron balls resting in their engines' spoons.

The engine commanders released their windlass locks. As the spoon bars slammed against the cross pieces, a series of deep thumps rolled across the hilltop.

One cross piece splintered. The bomb landed in front of the catapult and exploded, spraying hot shrapnel in all directions. Fifty feet away, a ball of flame engulfed four more catapults. A series of lesser explosions followed. An instant later, the splintered remains of four artillery pieces were raining down on the entire line of artillerymen.

Fortunately, that was the only misfire. Most of the bombs hit near the barbarian lines. At least half of the fuses went out before the missiles reached their targets. These powder pods simply burst on impact, spraying black sand everywhere. Of the bombs that did explode, very few landed close enough to inflict any casualties upon the enemy. Some even exploded in the air, over the Tuigan's heads.

The bombs' inaccuracy did not diminish their effect, however. The enemy's horses went wild, throwing their riders. Many thousands bolted, helpless men clinging to their backs. Within seconds, the Tuigan cavalry was fleeing in an uncontrolled panic.