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

Beiping. Prince Yan's Mansion.

Zhu Di stood on the high steps of the main hall of the Prince's mansion, the snow below swept and piled up again and again. Two months had passed since his return from Dongchang; the arrow wound on his arm had scabbed over, and when the scab fell off, a dark red scar remained. He would occasionally press that spot through his sleeve, not out of pain—but as a reminder to himself. Zhang Yu's memorial tablet was enshrined in a side hall, which he visited twice a day, morning and evening, staying only for the time it takes to drink a cup of tea each time. His expression upon leaving was exactly the same as when he went in, showing no change whatsoever. But Zhu Di knew that the Prince hung Zhang Yu's goose-feathered sword in his bedchamber, glancing at it every night before sleep.

Zhu Di did three things in those two months.

The first task was to reorganize the military system. The Yan army suffered nearly 30,000 casualties in the Battle of Dongchang, including not only Zhang Yu, but also over a dozen officers of the rank of chiliarch (or higher), and more than half of the lower-ranking officers below the rank of centurion. The three main guards of Yanshan—Left Guard, Right Guard, and Central Guard—were decimated, with some centurion units reduced to fewer than thirty men. Zhu Di urgently conscripted 20,000 new soldiers from Beiping and various guards, and borrowed 3,000 Mongol cavalry from the Three Guards of Doyan to supplement the vanguard. He trained them day and night to restore their organization. The veterans who survived the Battle of Dongchang were all reassigned to the new recruit camps as instructors, each leading ten new soldiers, teaching them everything from bayonet fighting and formation to flag identification.

Shen Du was one of these instructors. His centurion unit in Dongchang had suffered nearly half its losses, Zhao Laoliu's breaching squad had only four men left, Gu Zhang's swordsmen and shieldmen had five, Zheng Biao's third sword, which he had seized, had its blade chipped, and Huo Zhen's cavalry archers had only twelve riders returned. But these men were veterans who had fought their way from Baigou River to Dongchang, each one selected through countless battles. Shen Du divided the forty-odd new recruits into four groups, each with two veterans to train them—not in formations, but directly at the abandoned earthen walls outside Beiping City to practice siege warfare. He told Zhu Neng that these new recruits had never seen blood; a hundred days of standing in formation in the main camp was not as valuable as pushing a battering ram against a wall once. Zhu Neng allocated him the drill ground in the west of the city and also transferred twenty craftsmen from the artisan camp to help him modify siege equipment.

Shen Du redesigned the pointed wooden donkey. The original didnkey had a flat top; the sloping top allowed gunpowder canisters thrown from the city walls to roll to the sides instead of exploding on the roof. Removable iron plates were added to the side panels—in Dezhou, he had used cowhide curtains to block arrows effectively, but cowhide was too light and would crack after many lead bullets; iron, though heavier, could withstand musket fire. Most importantly, he replaced the wooden wheels with old iron-rimmed wheels salvaged from the supply camp's scrap heap, widening the axles by half a foot so they wouldn't jam when crossing trenches. This new equipment took an entire winter to build; the blacksmiths in the crafts camp worked day and night, even keeping their forges burning on New Year's Eve.

The second matter was rebuilding the scouting network. After the Battle of Dongchang, Shen Du made a suggestion to Zhu Neng, who then passed it on to Zhu Di. The core of the suggestion was just one sentence: the defeat at Dongchang was not due to the slow speed of the cavalry or the dullness of their weapons, but to insufficient intelligence. Sheng Yong's prior deployment of hidden trenches and poisoned crossbows showed that he was intimately familiar with the Yan army's cavalry's attack routes. Shen Du asked Zhu Neng to select a group of skilled horse archers from the Doyan Three Guards, and pair them with veteran surveyors from the Yan army itself, to re-establish a dedicated battlefield reconnaissance team. After Zhu Di approved, Shen Du borrowed six horse archers from Huo Zhen's men and four veterans from the centurions to assist him, repeatedly surveying the route from Beiping to Cangzhou, from Cangzhou to Jinan, and from Jinan to Dongchang. He recorded and mapped all the locations of ferry crossings, abandoned dikes, trench remains, and deer antler remnants in these areas, marking the impact of different seasons and weather conditions on cavalry marches on each map.

The third thing—endurance. Zhu Di was not a man who could stay idle, but he stubbornly endured an entire winter in Beiping. Winters in Beiping were long; from November to February of the following year, the icicles on the eaves never melted. Every day he rose at dawn to read military reports, went to the drill ground at noon to watch the troops train, went to the side hall in the evening to offer incense to Zhang Yu, and sat alone in his bedchamber at night studying maps until the lamp oil ran out. He was waiting for an opportunity. Jiahe.

March. The snow outside Beiping City had finally melted, the frozen ground began to soften, and the willow branches, withered all winter, sprouted a thin layer of green bark. Zhu Di spread out a map in the central military tent, pointing south along the Grand Canal to a point south of Daming Prefecture, where a tributary of canals crisscrossed the area. This was Jiahe. The river was only a few dozen feet wide, shallow enough for cavalry to ford directly. The banks were open alluvial plains, with no mountains to obstruct cavalry movement and a wide field of vision. Scattered reed beds and a few abandoned riverbanks along the river provided natural cover. Sheng Yong had deployed his forces in this area after his great victory at Dongchang, pushing his main force from Jinan into the heart of Hebei.

"Sheng Yong wants to attack Dongchang again at Jiahe." Zhu Di pointed to both banks of the Jiahe River. "The north bank is open ground, and the south bank is a gentle slope. Sheng Yong will choose the south bank to deploy his troops—the terrain of the riverbank is conducive to his use of the depth of his muskets and crossbows, as a direct frontal assault would result in too many casualties. But this time is different from Dongchang." He pushed a wooden war game piece across the river. "Sheng Yong's deployment habit is to have infantry in the front, muskets in the center, and cavalry in the rear, with the natural river channel used as cover on the flanks. The reeds on the west side are too dense, which is not conducive to the deployment of firepower. If we can cross the river here first to contain him, feign an attack to draw his main force to redeploy, and then take advantage of his formation change to launch a frontal assault on the middle section, he will not have the opportunity to leisurely set up multiple traps like he did at Dongchang."

After Zhu Di adopted this strategy, the person in charge of actually drafting and implementing it was Shen Du. He volunteered to lead the team to set off from upstream ahead of time.

Shen Du returned to the centurion's garrison and summoned Zhao Laoliu, Gu Zhang, and Huo Zhen to his tent. Under the oil lamp lay a rough sketch of the Jiahe terrain, which he had spent two months drawing. The forty-odd new recruits had trained all winter, never having seen real weapons, but these young men had been repeatedly drilled by the veterans into siege coordination and cavalry suppression, and most of them had endured the harsh training. Now, they stood outside the tent, silently preparing their arrows, only occasionally touching the movable iron plates on the side of the battering ram by the light of the snow.

"Sheng Yong is waiting for us on the south bank. The defensive line has been pushed far forward, and the musket positions are not far behind the waterline. He wants us to charge in the front, and then, like in Dongchang, to chip away at us layer by layer with muskets and crossbows." Shen Du lightly traced the location of the reeds on the sketch with his dagger. "But this time we won't cross the river from the location he chose. Huo Zhen, you take the mounted archers and circle around upstream. Set off before dark and swim across at night. Hide well in the reeds and keep an eye out. If there are people there, don't disturb them—if there are no people, just wait there for my signal."

Huo Zhen used his dagger to scrape at the horse's bones, then paused: "What's the signal?"

"Three gong sounds." Shen Du turned his head. "Upon hearing the gong, charge out from the reeds and attack the left rear of Sheng Yong's infantry formation. Don't linger in battle; fire only five volleys of arrows. After that, immediately disperse and retreat to the north bank—these mounted archers cannot be trapped like they were in Dongchang." His dagger moved towards Gu Zhang and Zhao Laoliu. "The main force will be led by General Zhu Neng to cross the river and launch a strong attack. Gu Zhang, you will lead the swordsmen and spearmen to form the first crossing team. After crossing, immediately deploy a crescent formation on the riverbank, piling sandbags into breastworks to block musket fire and secure the landing surface for the cavalry and battering rams. Zhao Laoliu, lead the breaching team and battering rams to cross with the second wave, dismantle the antlers on the south bank, and force open a passable opening on the front."

Old Zhao pulled his pipe out of his mouth: "Crossing the river—the water's not shallow, what if the wheels get stuck in the mud?"

"The supply battalion raised the chassis of the battering rams by half a foot and replaced the iron-rimmed wheels with wide-bladed wheels so they could roll on the riverbed. When crossing the river, they were pulled by three or four packhorses, and each battering ram was pre-installed with a top-mounted ferry rope; if it couldn't be pulled, it would be pulled." Shen Du inserted his dagger next to the sketch and stood up. "All new recruits, listen carefully—the Battle of Jiahe is the first battle for the Yan army after their defeat at Dongchang. Sheng Yong is waiting for us to lose again so he can take the opportunity to advance in full force. But we will not lose again. When Sheng Yong thinks we are still attacking using the old methods, Huo Zhen's arrow will pierce his left wing from behind the reeds—from this moment on, all he has left is the time we have disrupted."