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

Xu Huizu has left, but He Fu remains. Ping An is also there.

These two men lacked Xu Huizu's military talent and manpower, but they possessed something Xu Huizu lacked—familiarity with the terrain. He Fu had been stationed in the Huai River area for many years, and he knew every mountain road, every pass, and every pine forest suitable for hiding troops around Qimei Mountain like the back of his hand. Ping An retreated all the way from Zhengding to Qimei Mountain. Although he lost the battle, he did not give up. He gathered his remaining troops in Lingbi County, southwest of Qimei Mountain, using the city walls as the last line of defense, and transformed the mountain passes outside the city into a layered, deep defensive position.

The Southern Army had less than 60,000 troops remaining, of which He Fu's force of about 40,000 was stationed at the main peak of Qimei Mountain and the surrounding passes, while Ping An's force of less than 20,000 retreated to Lingbi. The two armies were mutually supportive—when the Yan army attacked Qimei Mountain, Lingbi would launch flank attacks to harass them; when the Yan army attacked Lingbi, Qimei Mountain would use its high ground to attack reinforcements. The ambush formation that Sheng Yong had set up at Jiahe was re-laid by He Fu at Qimei Mountain, except this time the ambush was not dug in a trench, but buried at the intersection of the valley and the pass.

The Yan army's first major assault on Lingbi occurred three days after Xu Huizu's withdrawal. Zhu Neng led 8,000 infantrymen up a gentle slope north of Lingbi, while Shen Du's centurion unit was responsible for flanking from the western hillside. However, He Fu had already laid an ambush on the hillside—not with musketeers, but with crossbowmen. The bolts from the drawn crossbows shot from the pine forest; the arrowheads were not coated with poison, but with a narcotic used by local hunters to hunt wild boar. Those struck would not die immediately, but within a few dozen breaths their limbs would be paralyzed, and they would collapse to the ground, only to be dragged away by the Southern army infantrymen hidden in the bushes.

Shen Du lost three soldiers on the mountainside. Zhao Laoliu's arm was grazed by a crossbow bolt; the wound wasn't deep, but the anesthetic made his left hand tremble for a whole day. He couldn't hold his pipe in his mouth and dropped it several times. He picked up the pipe, wiped it with his sleeve, and put it back in his mouth without saying a word, but Shen Du saw that his eyes were red—one of the three soldiers was a new recruit who had been learning to split deer antlers from him since Zhen Ding. He was only nineteen years old and was still calling out "Uncle Liu" when he was dragged away.

"This isn't Sheng Yong's style of fighting." Shen Du crouched behind the rocks, carving several lines into the stone with his dagger, his brow furrowed deeply. "Sheng Yong's musket formation is a direct confrontation, He Fu's style is attrition. He doesn't engage you in a head-on battle, he uses poisoned arrows to drag your men away one by one, until you're too afraid to venture into the woods. He can afford to wait, but we can't." He stuck his dagger into a crevice in the rock. "Our supplies won't last more than a few days."

The supplies were indeed running low. Each man had carried seven days' worth of dry rations when they set out from Dezhou, expecting to replenish them upon reaching the Huai River. Mei Yin had emptied the granaries on the south bank of the Huai River ahead of time, taking everything he could and burning what he couldn't. The Yan army had fought their way from Xuyi to Qimei Mountain, with very few towns along the way surrendering voluntarily. Supplies relied entirely on sporadic scavenging from abandoned southern army camps, sometimes available, sometimes not, and what they obtained was less than half of their daily consumption. The convoys sent by Zhu Di to collect grain along the way mostly brought back dried sweet potatoes and coarse rice from the nearby countryside, occasionally managing to bring back a few lean pigs. The quartermaster distributed all the meat to the wounded soldiers, while the rest continued to eat dry, hard biscuits.

A dysentery outbreak began in the army. The veteran soldiers from the north had never endured such humid and hot weather. Mosquitoes bred in the paddy fields and streams, and the well water used for heating in the kitchen was full of mud and sand. Some soldiers who drank the untreated water developed diarrhea and fever that very night. The army doctors had used up most of their herbal medicine during the siege and attrition warfare; the remaining medicine, boiled into a bitter broth, could only alleviate the symptoms, not stop the spread. In Shen Du's centurion's unit, five men were too ill to get up, lying on the supply wagons, delirious with fever. One of them was an old comrade who had followed him from Baigou River. Gu Zhang placed the last half-bag of dry rations beside the man's pillow, but the man didn't even have the strength to eat. Shen Du said nothing, simply placing his water bag beside him before turning and leaving the tent.

Plague and hunger were more terrifying than the sword of peace. No one in the tent dared to utter the words "take Nanjing immediately," but equally, no one mentioned retreat—Zhang Yu and Tan Yuan had lost their lives on this southward journey, and no one dared to be the first to utter the word "retreat." A silent anxiety permeated the air, heavier than the sound of gunfire.

On the evening before the Yan army's fourth charge was repelled at the foot of Lingbi City, Zhu Di finally blew out all the candles in the central command tent in one go.

He pushed the military report aside and went outside the tent alone. In June in southern Zhili, the night was not cool, the air was damp and sticky, and frogs croaked in the distant rice paddies. He stood at the tent entrance and looked up at the sky. There was no moon, only a thin layer of clouds overhead. His arrow wound on his arm had reopened after days of wielding his sword, and it still ached faintly, but he did not go to see the army doctor.

Zhu Neng, Chen Mao, Shen Du, and several officers of the rank of chiliarch or higher were summoned outside the tent. There were no desks or maps; everyone stood. Zhu Di stood silently with his back to them for a long time before turning around. His face showed no anger or resentment, only a calm that had settled after being pushed to the limit.

"Lingbi can't be taken. He Fu is on the mountain, and Ping An is in the city. If we attack the mountain, they'll attack our rear from the city. If we attack the city, they'll use crossbows to block our flanks. Our army's supplies are running low, and nearly 30% of our soldiers are sick. If this drags on any longer, even without He Fu's intervention, hunger and disease will wear down the entire army." His gaze swept across everyone's faces. "I know what you're thinking. Some say we should retreat to the Huai River to rest, others say we shouldn't—Zhang Yu and Tan Yuan can't have died in vain. But the situation is different now than Dongchang. Dongchang was caught off guard, and now it's slowly rotting away in the wetlands. If we don't make a decision soon, it will rot completely."

Zhu Neng stepped forward, his Adam's apple bobbing. His right arm had been wounded by an arrow during the fifth charge at Lingbi City, and now he knelt on one knee, his left hand gripping the hilt of his sword. "Your Highness—I request a retreat. Retreat is not defeat. We have marched south from Dezhou, covering a thousand miles, striking fear into the hearts of the Southern army. Now we are out of supplies and exhausted, so we should temporarily return north to rest and regroup, waiting for the summer heat to subside and autumn to return. I am willing to lead my troops to cover the rear and ensure the safe retreat of the entire army across the Huai River."

Chen Mao knelt down as well, saying only two words: "Please leave." The other commanders followed suit. No one mentioned Zhang Yu and Tan Yuan's names again, but their names were on everyone's lips—if they didn't leave, more people would die in the paddy fields of a foreign land.

Zhu Di's gaze finally settled on Shen Du. Shen Du stood leaning on his sword, his left leg clearly weak, but his back was ramrod straight. He met Zhu Di's gaze without kneeling.

"Your Highness, retreating is the only way to survive. But not all troops will retreat." Shen Du's voice was calm. "Lingbi City cannot be besieged—but Ping An must assume that we will continue the siege. If the entire army breaks camp and retreats north, He Fu and Ping An will immediately rush out from the mountains and the city to pursue us. They will chase us all the way to the Huai River. At that point, it won't be a retreat, it will be a rout."

Zhu Di looked at him and said, "Continue."

"Your Majesty, I request to lead my troops to garrison the Qimei Mountain pass. We don't need too many men—the existing forces of the Hundred Households plus a small number of mounted archers are sufficient. We should spread many flags at the pass, light many bonfires at night, and send cavalrymen to ride back and forth in the valley during the day, raising dust to create the illusion that the main army is still besieging us. When He Fu sees that the flags at the pass remain unchanged and the smoke from the cooking fires continues, he will not easily come down the mountain to pursue us. Your Highness should lead the main force to quietly retreat north under cover of night, and after crossing the Huai River, fire three fire arrows as a signal. When I see the signal, I will lead the garrison to withdraw from the pass and follow them."

Zhu Neng suddenly stood up: "No way! If you, a mere centurion, are left at the pass, and He Fu recognizes you and pounces, what will you use to defend yourself? Three or four thousand against forty thousand, you'll be crushed!"

"He won't be easily fooled." Shen Du's voice remained calm, as if he were describing a well-thought-out tactic. "He Fu is a cautious fighter and never takes risks. He won't launch an attack unless he's absolutely certain. Besides, our feints at the pass these past few days have made him accustomed to the Yan army gathering on the front lines, so he can't discern anything unusual when they're actually withdrawing. We'll use this feint until dawn, and by then the main force will be north of the Huai River."

Zhu Neng opened his mouth, then closed it again. He knew Shen Du was right. But he also knew that leaving the pass to defend was the most dangerous move in the entire retreat—once He Fu saw through the feint and attacked, those left behind would have almost no chance of survival. This wasn't an attack on the city, nor was it blowing up the city gate; it was gambling with the lives of dozens of men for a single escape window.

Zhu Di looked into Shen Du's eyes. This centurion had followed him since the Baigou River, blowing up city gates, setting up feints, and uncovering traps, while also suffering defeats at Dongchang and Qimei Mountain. He never boasted, never sought credit, and never uttered a superfluous word in military councils. Yet, his centurion's unit had dwindled from forty men to less than thirty, and Zhu Di had seen every name of the fallen in the military merit register—he remembered Zhao Laoliu, Gu Zhang, Zheng Biao, and also those young men dragged into the pine forest by drugged crossbow bolts.

"Granted." Zhu Di's voice was soft, but everyone heard it. "You stay and guard the pass. Remember—once you see three rockets, retreat immediately. Do not linger in battle, and do not hold out to the death."

Shen Du cupped his hands in a respectful gesture. "Understood, subordinate."

That night, the main force of the Yan army began its northward retreat. Zhu Neng personally arranged the retreat sequence, with the wounded and sick placed at the front, and the cavalry bringing up the rear. All the horses' hooves were wrapped in hemp cloth, and the cart wheels were bound with straw rope; the military order was, "Not a single torch is to be lit." The 60,000-strong army moved northward in the darkness along the valley west of Mount Qimei, the sounds of footsteps and cart wheels drowned out by the night wind and the rustling of the pine forest. From Mount Qimei to the Huai River, a distance of over a hundred li, the exhausted soldiers silently trudged along, while those weakened by the daytime heat staggered along, clutching the packhorses' girths.

Shen Du and his centurion remained at the Qimei Mountain pass. Huo Zhen volunteered to stay, selecting thirty skilled horse archers to mix with Shen Du's infantry. None of the original tents at the pass were dismantled; the campfires were still lit, and the banners were still flying. Zhao Laoliu and his men gathered all the broken armor and old weapons they could find in the camp and arranged them in formation, their outlines faintly visible in the firelight. Huo Zhen and his horse archers rode back and forth in the valley, branches tied to their tails, the dust they kicked up making it look like a large army was being mobilized in the night.

Shen Du stood on a rock at the highest point of the pass, leaning on his knife, watching the lights of He Fu's army on the main peak of Qimei Mountain to the south. Torches dotted the distant mountains, flickering in the night mist. He clutched the Southern Army's command flag, covered in carvings—the one torn from Baojia Camp, bearing the marks of every battle: Dezhou, Jinan, Dongchang, Jiahe, Gaocheng, and Qimei Mountain. He carved another line on the flag with his dagger. Then he tucked the flag into his robes and continued to gaze south.