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

That night, Shen Du leaned against a pillar on the south gate tower, resting his iron spear across his knee with his eyes closed for a moment. He hadn't slept for two days and two nights. The old injury in his left leg had flared up completely after the day's fierce fighting; his knee was so swollen it stretched his trousers tight. The herbal medicine Zhou Jing had applied to his knee dried quickly from his body heat, crumbling as it dried. He listened with his eyes closed to the sounds outside the city—bonfires, neighing horses, and faint human voices could be heard in the Qiang camp, but there was no sign of movement. Yao Chang had suffered considerable losses today; he wouldn't attack again tonight. He was certain of that.

But tomorrow will surely come. Tomorrow the battering ram will strike the siege gate again, and he has no idea how long that crack can hold. He opened his eyes, took out the bamboo slips from his robes, and flipped through them again by the dim light of the oil lamp on the crenellations. There weren't many records about Yao Chang on the bamboo slips; only a few scrolls mentioned the distribution of the Qiang tribe's troops and the location of their grain reserves. But one inconspicuous note made him stop in his tracks—"The Qiang people are accustomed to using inside agents. Before attacking a city, they always send someone to infiltrate it, either to set fires, spread rumors, or assassinate the defending general. In the past, when attacking Longxi and Tianshui, they used this method to break through the city's defenses first."

An inside man. During the day, when the battering ram was ramming the gate, several deserters were loitering near the control room of the south gate's sluice gate—not the soldiers guarding the south gate, their faces unfamiliar. They said they were transferred from the north gate to help, but they had no orders from Lao Wei. At the time, Shen Du was busy dealing with the battering ram and didn't think much of it. Afterwards, Lao Wei inspected the area, and those men were gone. They weren't deserters. They were Yao Chang's men. They had blended into the deserters and entered the city. During the day, they had scouted the city walls, seeing the cracks in the sluice gate and noticing the low oil reserves. They were now inside the city, hiding somewhere, waiting for the perfect opportunity—to burn down the granaries, open the city gates, or assassinate the commander.

Shen Du closed the bamboo slip and tucked it into his robes. He stood up, leaning on his iron spear shaft, and walked down the city wall. His left leg ached with every step, but he moved quickly, passing the soldiers and laborers still cleaning up the mess, until he reached the granary. The granary was located in the western part of the city center, a row of rammed-earth warehouses with tightly closed doors, guarded by four soldiers. The grain in the warehouse was running low, but it was the last bit of food for Chang'an. If the granary burned down, the garrison would collapse on its own before tomorrow evening. Old Wei followed Shen Du to the granary, where Shen Du whispered a few instructions before leaving his three most trusted brothers to guard the area. Before returning to the city wall, Shen Du paused, turning to Old Wei: "Pass down the order: double the guards at all crenellations. No shift changes tonight—those currently on duty continue, and those not on duty should all sleep on the city wall. Put your weapons nearby, and get up immediately at any sound."

He went to the wounded soldiers' camp. Zhou Jing was squatting on the ground, changing the bandage on a young soldier whose forearm had been pierced by an arrow. In the dim light, his expression was focused yet weary. Shen Du stood at the door without going in, simply placing the packet of herbs he had brought from Hangu Pass on the wooden shelf beside the doorframe. Zhou Jing looked up at him, said nothing, and simply nodded.

Meanwhile, in an abandoned house near the west gate of Chang'an, several people were talking quietly around an oil lamp. The Qiang people spoke rapidly, their tone urgent and suppressed. On the table lay a charcoal sketch, a simplified diagram of the south gate's heavy gate structure, the location of the cracks clearly marked. One of them gestured to the eastern section of the north city wall on the sketch, and a tall, thin man who had been silent suddenly spoke, whispering a few words in Qiang language—"Tonight's the operation."

Shen Du had returned to the city wall and squatted down beside Old Wei, whispering a few words in his ear. Old Wei nodded and turned to walk towards the alleyway leading to the granary. Shen Du then called Amu over and instructed him to divide the remaining usable kerosene cans into two portions: one to keep on the city wall for future use, and the other to be moved to the open space behind the granary. Amu asked him what he was doing, and Shen Du simply said, "Wait for my signal."

In the dead of night, a fire suddenly broke out in an abandoned stable in the south of the city. The fire wasn't large, but the flames were particularly conspicuous in the night sky, drawing the attention of the soldiers guarding the city walls almost simultaneously—someone shouted, "Fire in the south of the city!", others peered towards the fire, and a commotion arose on the walls. Then, a fire broke out in the west of the city as well—it was an abandoned hay shed; the dry hay had been doused with oil, and flames shot into the night sky, illuminating half the street. The soldiers' attention was completely diverted by the two fires, and no one noticed the unusual activity coming from the direction of the granary.

Four figures emerged from the dark, narrow alley behind the granary. They were dressed in the uniforms of the garrison soldiers, their footsteps light, clearly not ordinary defeated soldiers. The tall, thin leader gave a hand signal, and the other three quickly dispersed; two acted as lookouts, while the third followed the leader towards the outer wall of the granary. The leader untied several earthenware jars—oil jugs—from his waist, tied them together with thin hemp rope, and let the fuse hang from the mouth of the jar. He stuffed the oil jugs into a hidden drainage ditch at the base of the granary's outer wall, turned around and gave a hand signal, and the men behind him took out tinderboxes and brought them close to the fuse.

In that instant, in the open space behind the granary, Amu slammed the kerosene can he was holding to the ground—this was Shen Du's signal to him. The crisp sound of the shattering can was extremely penetrating in the silent night, and immediately afterward, more than a dozen torches lit up around the granary. Old Wei led his men out of the alleyway in front of the granary, followed by more than twenty infantrymen who were on high alert, archers standing up on the rooftops on both sides, nocking their arrows. Shen Du emerged from the shadows on the side of the granary, the short knife in his hand gleaming coldly in the torchlight.

"Light the fire," he said. He wasn't speaking to the Qiang people, but to Old Wei.

Old Wei threw a torch into a shallow ditch he had dug beforehand around the granary. A layer of dry grass soaked in kerosene lined the ditch, and flames quickly spread along it, forming a raging fire encirclement around the granary, completely blocking the Qiang people's retreat. The tall, thin Qiang man's pupils contracted sharply. He tried to move the tinderbox towards the fuse, but the moment his finger moved, a crossbow bolt shot down from the roof and pierced his wrist, the tinderbox slipping from his hand and rolling into the fire. Immediately afterward, a second bolt pierced the thigh of his companion behind him, who screamed and collapsed to the ground. The other two Qiang lookouts turned to run, but were shot down at the alleyway entrance by a volley of arrows from the rooftops. The tall, thin man knelt on the ground, clutching his wrist, his face covered in sweat, but his eyes didn't show fear—but rather an incredulous astonishment. They had planned to scout and infiltrate, eliminating the visible sentries around the granary beforehand; it should have been foolproof.

Shen Du walked through the ring of fire to stand in front of him. Flames licked the dry, cold air behind him, casting his shadow, twisted and enormous, onto the rammed earth wall.

"You drew the cracks in the sluice gate," Shen Du said. (This is not a question.)

The tall, thin man stared at him without saying a word.

"You have a contact at the North Gate; he's been lurking among the garrison for a few days now." Shen Du squatted down and tossed the broken pieces of the kerosene can in front of the tall, thin man. "Your plan is to burn the granary tonight, and tomorrow, in the chaos, open the North Gate to help Yao Chang attack the city." The tall, thin man's face twitched, but he quickly suppressed it. However, Shen Du still noticed the shock in that instant—this man hadn't expected a centurion from the Former Qin to know so much.

He didn't continue the interrogation. For these assassins, the moment they were exposed, they were already prepared to die; further interrogation was just a waste of time. Shen Du stood up and said to Lao Wei, "Keep him alive and send him to the military advisor. Make him write down the list of the Qiang people lurking in the city—it doesn't matter if he doesn't, the arrow he carries, the one from Yao Chang, is enough." After the tall, thin man was taken away, Shen Du squatted down and picked up the tinderbox that had been shot down by an arrow from the shallow ditch. The tinderbox was exquisitely crafted, with the Qiang totem—a soaring eagle—engraved on its copper casing. He turned the tinderbox over to look at the bottom, where a small character "Yao" was engraved. This was equipment from Yao Chang's personal guard.

"Old Wei, move all the wounded to the barracks near the West Gate. Disperse the grain in the granaries and store it along the various sections of the city wall. Don't leave a single grain in place. Report back immediately after you've interrogated the group of people we captured tonight. Tomorrow, when Yao Chang comes to challenge us, let him do it outside the city."

As dawn broke, bugles sounded once more outside Chang'an. Shen Du stood atop the south gate tower, watching the Qiang army regroup and form ranks outside the city. The battering rams had been repaired and pushed to the forefront of the formation, their iron heads gleaming coldly in the morning light. Qiang infantrymen carried newly constructed siege ladders forward from the rear ranks, their numbers even greater than the day before. Yao Chang's command banner unfurled in the morning breeze, beneath which his generals pointed and gestured towards the city walls.

Then the city gate suddenly opened. It wasn't that the heavy gate had been breached—the defenders opened it themselves. The south gate was half-open, and a group of infantrymen carried several heavy wooden crates to the outside of the city gate. They placed the crates on the ground, opened the lids, then turned and retreated back into the gate opening, closing the gate again. The crates contained the armor and weapons of the Qiang traitors who had been annihilated the previous night, with the copper-cased tinderbox engraved with the character "Yao" on top.

The Qiang phalanx outside the city remained silent for a long time. This silence wasn't fear—it was embarrassment. Their psychological warfare had been exposed on the spot, their inside man had been wiped out, and even their tokens had been left unattended at the city gate. The impact on morale was far greater than the loss of a direct confrontation. Yao Chang stood under his command flag for a long time, then whispered a few words to his deputy. The deputy obeyed the order, spurred his horse forward, this time without a white flag, and charged directly to the city wall, shouting in the Guanzhong dialect: "Listen up, city wall—if you don't surrender today, none will be spared after the city falls tomorrow!" After shouting, he didn't wait for a response and immediately turned his horse and retreated back to his own lines.

No one on the city wall spoke, but everyone's hands were steadied. Old Wei slammed his spear against the crenellation and said to the messenger, "Go back and tell Master Shen we can fight today." The messenger quickly ran down the city wall towards the granary. Shen Du stood on the city wall, watching the commander's flag fluttering in the wind opposite—the inside man had been eliminated, and Yao Chang was left with only a direct assault. And a direct assault was the fighting style he feared least.