In this realistic war game, only I understand the course of the battle.

On the fifty-ninth day of the siege, the ice on the Wei River cracked from the sound of drums.

It wasn't the Qiang people's drums—Shen Du had been listening to the Qiang drums for nearly two months; they were dull and rapid, like the low growls of a wild beast rumbling in its throat, each sound signifying a new charge. But this time was different. This time, the drums came from the north, from the direction of the Xianbei camp. The drumbeats were heavy and rhythmic, each beat striking the frozen ground, causing broken bricks to fall from the city walls.

Shen Du stood atop the south gate tower, still clutching the military report he had just finished writing. He turned to look north—the gates of the Xianbei camp were all open, and cavalrymen filed out, not just scouts of a few dozen men, but organized cavalry squares. Their armor gleamed in the morning light, forming a dazzling band of light, and the hooves of their horses pounded the thin ice on the frozen ground with a deep, rhythmic roar. Murong Chui's banner slowly unfurled in the morning breeze; it was a large black banner embroidered with Xianbei totems—a gyrfalcon with outstretched wings, its claws gripping a snake. The snake was the totem of the Qiang people.

Murong Chui has launched an attack. This is not a test, nor a show of force; it is a genuine military campaign.

"What time is it?" Shen Du asked.

"It's just past Chen Shi (7-9 AM)." Old Wei's deputy stood beside him, gripping a spear in his hand, his knuckles white.

Shen Du raised his binoculars, aiming them at the Xianbei cavalry formation. The cavalry was divided into three echelons—the first echelon was light cavalry, their horses unarmored, the riders carrying only scimitars and short bows, responsible for rapid infiltration; the second echelon was heavy cavalry, both rider and horse clad in iron armor, wielding long spears whose tips gleamed coldly in the morning light; the third echelon was mounted archers, their saddles laden with quivers, bowstrings taut in the cold wind. The three echelons were meticulously organized, with light cavalry in the vanguard, heavy cavalry in the center, and mounted archers on the flanks, their formation resembling an open fan. This was not a spur-of-the-moment attack; it was a pre-arranged battle sequence. Murong Chui had been waiting in his camp for two months, anticipating the perfect opportunity.

The bugle call sounded. The Xianbei bugles were sharp and high-pitched, three long and one short—this was the charge. The first echelon of light cavalry moved first, their hooves kicking up clouds of dust, charging straight into the western flank of the Qiang phalanx. The Qiang archers hastily turned to meet the attack, but before the first volley of arrows could be fired, the Xianbei light cavalry's shortbows had already struck first—the light cavalry fired while on the move, arrows ricocheting from the side into the Qiang archers' ranks, felling a row of Qiang archers, tearing a gap in their formation. The second volley followed closely, this time aimed at the Qiang infantry phalanx. The arrows pierced the infantry's leather armor, embedding themselves in the frozen ground with a series of muffled thuds, and the Qiang infantry retreated in panic, colliding with the reserve ranks at the back.

Immediately following, the second wave of heavy cavalry surged forward. Without firing arrows, the heavy cavalry charged directly, their hooves crushing the last line of barricades in front of the Qiang ranks, their spear tips piercing the shields of the front-line shield bearers. The sounds of shattering shields mingled with screams of agony as the Qiang's shield formation was shattered in the first wave of the heavy cavalry's charge. Yao Chang's deputy attempted to organize a counter-charge, but the Qiang cavalry hadn't even had time to form ranks before the Xianbei heavy cavalry broke them up from the flank. The horses, terrified, ran wildly in all directions, trampling down large numbers of their own infantry.

The third echelon of mounted archers spread out on both flanks, unleashing a hail of arrows that pinned down the rear of the Qiang phalanx. The Qiang were attacked from three sides—arrows from the defenders of Chang'an city walls in front, short bows from Xianbei light cavalry on the sides, and long spears from Xianbei heavy cavalry behind. Under this three-pronged attack, the Qiang phalanx began to crumble from the edges towards the center.

Shen Du, standing atop the city wall, witnessed everything clearly. The Xianbei cavalry's flanking maneuver was incredibly precise—they bypassed the thickest shield formation of the Qiang front, cutting in from the weakest point on the flank. They used the short bows of their light cavalry to disrupt the archers' formation, then used the long spears of their heavy cavalry to break through the advancing infantry square, finally flanking from both sides with mounted archers. He had seen this tactic countless times on the battlefield. Murong Chui was a true cavalry commander; he had maximized the Xianbei cavalry's speed advantage.

"Pass on the order!" Shen Du turned and roared at the messenger, "Captain Zhu—take all the mobile infantry from the north gate out of the city and flank the Qiang phalanx from the flank and rear, coordinating with the Xianbei cavalry to squeeze them into the center. Remember, don't attack head-on, attack the fleeing soldiers, drive them towards the Qiang main force, let them trample themselves!"

Commander Zhu received the order at the foot of the city wall and led eight hundred infantrymen from the north gate out through the east side gate. Instead of forming a square formation, they split into more than a dozen small teams, crept along the shadows of the city wall towards the flanks and rear of the Qiang people's square formation.

Meanwhile, Shen Du ordered the oil-making team to carry the last few pots of oil to the south gate's crenellations. "Burn them all. Don't skimp," he said. The defenders carried the iron pots to the crenellations and poured them down, the boiling oil splattering onto the heads of the Qiang infantrymen below the city wall. Screams of agony echoed below the wall. Immediately afterward, rockets were launched, striking the oil-soaked ladders and corpses. A wall of fire, stretching for dozens of feet, erupted at the base of the wall, black smoke billowing into the sky, completely blocking the Qiang's view.

Shen Du descended the city wall and walked to the inside of the city gate. He drew a short sword from his waist and said to the garrison commander, "Roll up the gate and open it."

The defenders on the city wall were stunned—this gate had never been raised during the two months of siege. But no one questioned Shen Du's order. The heavy iron chains of the gate were slowly cranked up by the winch, the rusted cracks creaking as they were pulled. The city gate was pushed open a crack, and Shen Du, along with Lao Wei and two squads of carefully selected swordsmen and shieldmen, rushed out of the gate. A burning sensation surged through his feet—the passive state of a soldier crossing the river was fully activated as he faced the enemy. Every step gave him strength. He charged at the forefront of the swordsmen and shieldmen, cleaving down a Qiang captain blocking the gate with a single stroke, the blade cutting between his shoulder armor and neck guard, drawing a spray of blood as it was pulled out. Lao Wei followed closely behind, his spear piercing the chest of a second Qiang man. The swordsmen and shieldmen behind him formed a crescent formation outside the city gate, their shields clashing together with a dull thud, and spear tips protruding from the gaps in the shields, aimed at the retreating Qiang infantry directly in front of them.

From the moment the Xianbei cavalry charged into the enemy lines to the complete collapse of the Qiang, less than an hour had passed. Yao Chang attempted to rally the routed soldiers and regroup them under his command, but they refused to obey orders. Commander Zhu's eight hundred infantrymen, advancing from the flank and rear, specifically targeted the routed soldiers—avoiding direct combat and instead chasing them towards the Qiang main force. The routed soldiers overwhelmed Yao Chang's last reserve force; horses trampled each other, infantry pushed and shoved, and the entire battlefield descended into chaos. The Qiang square formation completely crumbled, their troops fighting independently. Some threw down their weapons and fled to the north bank of the Wei River, others knelt and surrendered, and several tribal leaders, along with their personal guards, abandoned the battlefield and retreated westward. Yao Chang himself was dragged from the battlefield by his guards and hastily retreated northward to his main camp north of the Wei River.

As dusk fell, the shouts of battle outside the city finally ceased. Half of the Qiang camp had been trampled flat by the Xianbei cavalry, and the tents were ablaze, their flames illuminating half the sky. The defenders on the city walls silently watched the scene outside—after being besieged for nearly two months, this was the first time they had seen the Qiang camp collapse in flames.

Shen Du stood on a high slope outside the city, watching the routed Qiang soldiers disappear into the direction of the north bank of the Wei River. He did not pursue them—although Yao Chang had been defeated, his main force was not entirely wiped out, and after retreating to his camp north of the Wei River, he still had the ability to regroup, and the pressure of the siege would not be relieved immediately. More importantly, Murong Chui's Xianbei cavalry, after defeating the Qiang, did not continue the pursuit but stopped at the ruins of the Qiang camp, collecting their spoils. Murong Chui's expedition was not to save Chang'an, but to seize territory. But for now, Chang'an could at least breathe a sigh of relief.

"Master Shen," Old Wei caught up from behind, bending down to pick up a torn Qiang banner from the ground. His face was streaked with black and white from the soot, and he grinned, "That felt good! After being surrounded by these bastards for so long, I finally got my revenge today!"

"Don't be so happy yet," Shen Du said. "Yao Chang is not dead yet, and the Xianbei are still outside the city."

"Weren't the Xianbei people helping us?"

"They're helping themselves. The siege isn't over yet, and the next battle might be even harder." He sheathed his knife, turned, and walked towards the city wall. "Tonight, gather all the arrows we can. We've run out of oil; starting tomorrow, we'll have to use boulders and logs. Have Zhou Jing recount the wounded soldiers in the wounded battalion, and add all the able-bodied ones to the crenellations. Also, reinforce the cracks in the sluice gate with iron hoops and wet ropes tonight; get it done quickly."

That night, on the north bank of the Wei River, Yao Chang sat in a makeshift tent, his armor still covered in the dust of the day. Before him lay a fragment of a military report salvaged from the battlefield, bearing only half a line: "Murong Chui has reached an alliance with the garrison commander of Chang'an." This line had been deliberately left on the battlefield by Commandant Zhu at Shen Du's behest, written in charcoal on a tattered cloth and mixed with the belongings of fallen Qiang soldiers. Yao Chang held the tattered cloth by the candlelight for a long time, his expression shifting between light and shadow in the flickering candlelight.

"Alliance." He muttered the word to himself, then looked up at his deputy and said, "Murong Chui has indeed joined forces with Fu Jian. Issue the order—the entire army must retreat to Anding tonight, abandoning the Weibei camp. Chang'an cannot be besieged anymore; continuing the siege will only result in being attacked from both sides."

The lieutenant hesitated for a moment: "General, although the Xianbei people sent troops today, they did not pursue us—"

"No pursuit?" Yao Chang suddenly laughed, his laughter dry and sinister. "You think Murong Chui is fighting a war? He's giving me face. He's not pursuing me, waiting for me to retreat voluntarily. If I don't retreat today, he'll join forces with the Chang'an garrison to attack me tomorrow. Murong Chui never does anything that doesn't benefit him—he's waited two months for the perfect opportunity. Now the time has come. Retreat."

Messengers ran through the camps all night, and the remnants of the Qiang people began their westward retreat before dawn. Tents were dismantled and loaded onto carts, the wounded were carried onto packhorses, and arrows and oil canisters from the armory were repacked and transported. By daybreak, the Qiang camp on the north bank of the Wei River was empty, leaving only charred ruins and the haphazard remains of siege equipment. Battering rams were abandoned on the mudflats of the south bank of the Wei River, their iron heads stuck in the icy water, the ropes still entangled with broken arrows shot from the city walls. Half of the siege ladders were charred and leaned against the base of the city wall, a Qiang flag, pierced by arrows and blackened by smoke, still hanging on its body.

Shen Du was the first to discover Yao Chang's retreat. He stood on the city wall, watching the thinning smoke rising from the Qiang camp for a long time, then turned and walked inside, sat down against the wall, rested his iron spear shaft across his knees, and closed his eyes. He had been guarding the city wall for countless days and nights, and the old wound in his left leg had completely gone numb. Old Wei came over and gently covered him with a blanket captured from the Qiang camp. He slept soundly, his breathing steady and quiet, still clutching the breastplate in his hand.

Murong Chui sent a messenger to the city walls at noon that day. The messenger was an elderly Xianbei captain who spoke the Guanzhong dialect. He stood on horseback outside the city gate, looked up at the city tower, and shouted: "General Murong says that the siege of Chang'an has been lifted, and the Xianbei tribe is willing to defend Guanzhong with the Qin army. Please send the defending general out of the city to meet with me and discuss the joint defense."

Shen Du listened to the old captain's words from the city wall. He didn't respond immediately, but instead scanned the Xianbei cavalry formation outside the city with his binoculars. The cavalry formation remained near the ruins of the Qiang camp, neither advancing towards the city wall nor moving towards the Wei River. Although Murong Chui's men verbally agreed to defend together, their positioning revealed their true intentions—he was waiting to see Shen Du's attitude. If Shen Du appeared weak or impatient, Murong Chui would press forward. If Shen Du appeared calm or even firm, Murong Chui would maintain the facade of cooperation.

Shen Du replied to the old captain below the city walls, "Thank you, General Murong, for your help in relieving the siege. The Qin army is short of supplies and cannot come out of the city to meet us. Please rest and regroup north of the city until the supply lines to Chang'an are restored, then we will reward you. The first step in jointly defending Guanzhong is to clear the corpses below the city walls and prevent the spread of plague. If your army has the capacity, please assist in the burial." His words contained neither refusal nor flattery, positioning Murong Chui as an "assistant," neither master nor enemy. The old captain, after hearing this, said nothing more, cupped his hands in greeting, and rode away.

After listening to the old captain's account, Murong Chui remained silent for a while, then said to his deputy, "This man has defended the city for nearly two months. He neither surrendered nor fled, nor did he immediately come out of the city to curry favor with me after Yao Chang withdrew his troops. Either he is fearless because he is confident, or he truly doesn't care about life or death. Either way, he is not easy to deal with."

A few days later, Old Wei returned from Lantian. When he pushed open the city gate and walked in, he was emaciated, his lips were cracked and bleeding, his armor was torn to shreds by the rocks and hung like rags, and his arms had several new scars, but his eyes were extremely bright. He said he had taken Azhi to Lantian, where he found an old merchant willing to take her to Hebei, and gave the merchant all the silver Shen Du had given him for travel expenses. Then he traveled back overnight, avoiding the Qiang patrols, crossing mountains and valleys for several days before finally returning to Chang'an. Shen Du helped him up and said that he already knew about Azhi's situation, and it was good that he was back.

"That girl, Azhi, asked me to give you a message." Old Wei took something out of his pocket and handed it to him. It was a red string knot, the same knot as the one Amu had worn before, but the color was new, made with Azhi's own red string. A small piece of bark was tied to the knot in charcoal—"The ledger is on page seven. There are still five bags of millet left in the granary. Azhi."

Shen Du clutched the peace knot in his hand. This red string wasn't a talisman; it was a promise—the last words a small, thin girl, who had learned to write the characters "Amu" while holding an account book, said to him as she turned back from the mountain path in Lantian. She had turned to the seventh page of her brother's account book, and she would continue turning it. He tied the peace knot to the hilt of the short knife at his waist, stood up, and walked outside.

Outside the city, smoke still rose from the ruins of the Qiang camp, and Xianbei banners fluttered in the cold wind. Beneath those banners, Murong Chui awaited his response. He knew every step from here on would be more difficult—Murong Chui wouldn't be content with merely playing the role of "assistant." Yao Chang had retreated, but his main force remained, and after withdrawing to the north of the Wei River, he could return at any moment. Meanwhile, Chang'an's food supplies were dwindling, its oil exhausted, and it had fewer than a hundred arrows. The cracks in the city walls, though temporarily reinforced with iron hoops and wet ropes, couldn't withstand another slam of battering rams. He needed time, he needed food, he needed Murong Chui to temporarily refrain from turning against him—he had none of these bargaining chips. But he possessed something Murong Chui lacked—he had defended Chang'an. The city still stood, Fu Jian still stood, and the Qin army's banners still flew atop the city walls. As long as the city remained, there was still a chance to turn the tide. He pushed open the door and stepped into the hazy morning light of Chang'an. Old Wei followed behind, leaning on the spear that was blackened by kerosene.