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

Seven days after Azhi left, horns sounded again from the Qiang camp outside the city. Shen Du stood on the south gate tower, watching the Qiang phalanx advance simultaneously from the north, west, and south. Battering rams were pushed to the front of the south gate, and siege ladders carrying newly made ladders flanked the city from both sides. Archers formed three horizontal lines behind their shields, their arrowheads bound with hemp cloth soaked in kerosene. This time, Yao Chang did not send anyone to persuade them to surrender, nor did he resort to any tricks—he deployed all available siege equipment to the front lines. The siege had lasted nearly two months; the city's food supplies were running low, and the defenders on the walls were exhausted. This was the moment he had been waiting for.

But just as the Qiang phalanx advanced to within three hundred paces of the city wall, a horn suddenly sounded from the Xianbei camp to the north. This horn was completely different from the Qiang horns—the Qiang horns were deep and resonant, while the Xianbei horns were sharp and high-pitched, like a fine knife slicing through the winter sky. Immediately afterward, the gates of the Xianbei camp opened, and a cavalry unit filed out, forming ranks on the open ground outside the camp. The Qiang siege force halted. The infantrymen pushing the battering rams turned to look north, the laborers carrying ladders put them down and straightened their backs to peer, and even the archers released their bowstrings and turned to look in the direction of the Xianbei camp.

Shen Du lowered his binoculars and tapped his fingers lightly twice on the crenellated bricks. The letter he had sent with Azhi had worked—but he wasn't sure if Murong Chui was truly going to send troops or was just testing the waters. Although the Xianbei cavalry had formed ranks, they didn't advance towards the Qiang camp or towards Chang'an. They simply remained on the open ground outside the camp, neither attacking nor retreating, as if waiting for something.

Meanwhile, news arrived from the north gate: Commandant Zhu of Liang Commandery had sent a messenger. The messenger was a thin, young Di man who, after setting out from Liang Commandery, bypassed the Qiang blockade and traveled for a day and a night along the northern foothills of Mount Li before finally reaching Chang'an. The news he brought back made Shen Du frown—Xianbei scouts had appeared on the outskirts of Liang Commandery. At first, only a few scattered riders were seen peering into the distance, but their numbers gradually increased, and they set up a temporary camp in the hilly area north of Liang Commandery. The Xianbei scouts did not attack the city, nor did they engage the Qin garrison; they simply remained there. Murong Chui was probing. The Liang Commandery garrison numbered only a few hundred; if the Xianbei cavalry were to truly attack, Liang Commandery would not be able to hold out for long.

Shen Du quickly wrote a reply on the back of the military report with charcoal: "Prioritize defending the city; do not launch any offensives. Observe the movements of the Xianbei people and report back immediately if anything happens." He folded the report and handed it to the messenger, then took out the last bit of silver from his pocket and stuffed it into the messenger's hand so he could exchange it for food on the way. The messenger bowed and hurried away.

"Master Shen, judging from today's situation—" Old Wei's deputy leaned over and whispered, "Are the Xianbei people going to help us?"

"I don't know," Shen Du said.

"So what do we do?"

"Wait." Shen Du turned and walked towards the inner side of the city wall. "Tell everyone not to let their guard down. No matter what happens outside the city, our only task is to defend the city."

That night, the oil lamps on the south gate tower burned all night again. Shen Du sat behind the crenellations, rereading the bamboo slips in his arms. He had read the records about Murong Chui on the bamboo slips many times, but this time he noticed a detail he hadn't paid much attention to before—"Murong Chui is cautious in his military tactics, and he doesn't go out unless he's absolutely certain." Absolutely certain. Murong Chui wouldn't gamble everything before the situation became clear; he would only put the last feather on the lighter side when the scales were about to tip. Shen Du closed the bamboo slips, stood up, and walked to the edge of the crenellations, gazing at the lights of the Xianbei camp to the north of the city. A thought suddenly popped into his head: Murong Chui's deployment of troops today wasn't to see Yao Chang's face, but to see the walls of Chang'an. He wanted to confirm whether the city could still be saved—whether it was still worthwhile to continue observing.

Shen Du stood by the crenellations for a long time, then turned around and said to the messenger on duty, "Go and recall Commander Zhu from the west gate. Also, gather all the wounded soldiers who can still stand up and bring them to the north gate wall—have them put on armor and stand on the crenellations. Light twice as many torches as possible, make the wall as bright as possible."

The messenger paused, then asked, "Wounded soldiers are coming up the city wall? They can barely walk—"

"They don't need to walk, they can just stand," Shen Du said. "Let them lean against the battlements, weapons in their hands. I want the people on the other side to see that there are still tens of thousands of soldiers guarding the walls of Chang'an."

The reply will reach Hebei in a few days, at which time Murong Chui will make his final decision. But Shen Du doesn't know if he can wait that long. What he needs to do now is to keep Chang'an standing until Murong Chui makes his decision.

The next morning, several hundred wounded soldiers appeared on the north gate city wall. Some leaned on crutches, some had slings, and some still had bleeding wounds on their foreheads. Zhou Jing used the last bit of charcoal to paint rosy cheeks on each wounded soldier's face—he said it would make them look healthier from a distance. Shen Du stood at the highest point of the city wall, watching these soldiers being helped out of the wounded camp one by one by Zhou Jing, saying nothing, only nodding to them. Old Wei's deputy, with several soldiers who could still run, walked back and forth on the city wall, changing positions each time they went, which from a distance looked like reinforcements being frequently moved around.

On the earthen ridge north of the city, Xianbei scouts rode back and forth. They saw the walls of Chang'an filled with garrison troops, the torches behind the crenellations stretching from east to west, and the flags on the city towers fluttering in the morning breeze. The scouts turned their horses and rode north. An hour later, the gates of the Xianbei camp opened again—this time even more cavalry emerged, forming a neat square formation outside the camp, facing the Qiang camp. Murong Chui was flexing his muscles. He hadn't decided who to attack yet, but he was telling everyone: I have soldiers, I have horses, I have the choice.

On the same day, in the Qiang camp outside the city, Yao Chang stood outside his tent, facing the Xianbei camp. His deputy rode back from the north, dismounted, and whispered a few words of report—the Xianbei forces hadn't increased much; after forming ranks, they remained stationary, neither advancing nor retreating. Yao Chang twirled his whip a few times in his hand, said nothing, and simply turned and walked back to his tent. He didn't withdraw his troops, nor did he order a continuation of the siege; he simply ordered his troops to continue the siege while simultaneously diverting a portion of his forces to the north for defense. The greatest weakness of a suspicious person isn't distrust of others—it's the inability to make decisions at crucial moments.

This was the coldest day since the beginning of winter. The Wei River was completely frozen, the ice so thick you could walk on it. White smoke rose from the bonfires of the Qiang camp outside the city, mingling with the damp air at the foot of Mount Li, shrouding the entire plain in a grayish-white mist. Shen Du sat on the city wall, leaning against the crenellations, watching the banners of the Xianbei camp appear and disappear in the mist. He took out the breastplate that Old Wei had given him from his pocket and weighed it in his hand. The breastplate was made of iron, very heavy, with a few nicks along the edges, but it had been polished so it wouldn't cut his hands. Old Wei was still on the mountain road in Lantian, leading Azhi towards Hebei. Commander Zhu had been guarding the west gate for several days, Zhou Jing was using the last of his medicine to change the bandages of the wounded soldiers in the wounded soldiers' camp, and Azhi had reopened Amu's account book, the two characters "Amu" scrawled crookedly on the cover. Everyone still alive in this city was doing what they were supposed to do, and he had no reason to stop.