"...Revered Immortal, though the skies over the capital have now cleared and the snow has ceased, the chill yet lingers in the marrow — a frost so bitter that water freezes the moment it drips. Our garrison troops suffer day and night upon the ramparts, exposed to this merciless cold. Yet owing to the isolation between the inner and outer city, firewood and charcoal for warmth are in grievous shortage, and even the stones needed for our catapults are difficult to procure... Apart from dismantling structures and felling trees within Genyue, we have little choice but to tear down civilian dwellings, thereby disturbing the common folk..."
Upon the dusty grounds of the demolition site at Genyue, Zhang Shuye wore a solemn countenance, his expression marked with a sorrowful gravity as he addressed Guo Jing with due ceremony:
"These past days, many soldiers stationed on the ramparts have succumbed to frostbite in the night. Conflicts have even broken out between our troops and the people during the forced dismantling of homes in search of timber. This official can endure it no longer, and thus humbly beseeches the Immortal to show mercy — to reopen Genyue, so that the imperial troops may draw upon its resources for relief."
As he spoke, he bent low in a deep bow, earnest and unwavering.
— Alas, this man cloaked in righteous integrity, though sharp of mind, had nonetheless been swayed by the seasoned scoundrels of the Forbidden Army.
As for the use of ornamental Taihu stones as makeshift artillery — a profligate waste — Wang Qiu and his companions had voiced no complaint; after all, such rocks bore little value in the modern age. But to watch them mindlessly split fine timber to fuel their fires — that was another matter entirely. That hurt.
More to the point, Guo Jing — a veteran of Bianjing's inner workings — instantly saw through the imperial troops' unsavory intentions to "fatten their purses" beneath the guise of requisitioning. The treasures of this royal garden were, after all, paid for with the desperate coin of a debt-ridden Doraemon — how could they be squandered so lightly? To acquiesce now would be to throw open the granary to rats, to welcome wolves into the henhouse.
And yet, a direct refusal would be ill-received — perhaps even be deemed sabotage of the war effort. Fortunately, in moments such as these, Wang Qiu had a knack for thinking sideways — reaching beyond the chessboard to conjure the most unorthodox of gambits.
"...Doraemon," Wang Qiu murmured, tapping his friend gently on the back, "could you bring out your Weather Controller once again?"
"Hm? Sure I can!" Doraemon replied, blinking. "But what for?"
"Well, obviously, to solve the cold-weather crisis those poor troops are facing on the ramparts. Your device can manipulate temperature, can it not? If they keep complaining about the freezing air, why not simply raise the temperature so high that they'll have no need for fires at all?"
"...Ah! That makes perfect sense!" Doraemon exclaimed. "What a clever idea — I'll try it right away!"
Thus, only moments later, Guo Jing — discreetly informed of this scheme — delivered a response to Zhang Shuye that left the latter utterly dumbfounded:
"Master Zhang, I have heard the plight of the garrison. Yet to kindle fires for warmth addresses the symptom, not the root. Since the city now lacks sufficient fuel, rather than fell more timber, why not allow this humble Daoist to conduct a ritual and command the heavens to turn warm? What say you to that?"
What followed left Zhang Shuye speechless in disbelief:
The very same afternoon, the temperature in Kaifeng soared from -18°C to +42°C — a staggering leap of 60 degrees in mere hours.
— In the blink of an eye, the bitter chill of winter gave way to the blistering scorch of summer. Icy winds turned to searing gusts. The Song defenders atop the walls and the Jin besiegers below were equally stunned into silence.
And soon, beneath this surreal reversal of seasons, thousands began to collapse from heatstroke, felled one after another...
...
In the depths of winter, the sun now blazed like midsummer — a suffocating inferno blanketing Bianjing and its outskirts.
Even within the city, the Song citizens found themselves drenched in sweat, heads spinning and vision swimming — a heat so cruel that even the so-called "furnace cities" of later ages might pale in comparison. Only the likes of Indians, perhaps, could bear such heat unflinching.
As for the Jurchen warriors, born of the frigid forests of the north and long inured to cold but not to heat, it was nothing short of hellish.
...
Beyond the city, in the Jin encampment at Qingcheng Fort:
That morning, General Wanyan Zongwang of the Eastern Route Army awoke from his slumber drenched in sweat, his body hot to the touch, soaked from head to toe.
Though dawn had just broken, the air inside his tent already hung thick with oppressive heat. Even sitting still, sweat poured forth as if from a leaky vessel. Breathing was a chore. Mosquitoes buzzed incessantly, their torment robbing him of rest — he no doubt bore dark circles beneath his eyes by now.
As a battle-hardened warrior of the north, Zongwang had never dreamed that November could bring such stifling warmth.
In his homeland by the Songhua River, this time of year saw water freeze solid and saliva crystallize mid-air. Even days ago, snow and gale howled outside Bianjing, the Yellow River locked in ice. The sight of shivering Song soldiers atop their walls had drawn only sneers and scorn from his men.
But now?
Clear skies stretched unbroken, the sun scorched overhead, and not a breeze stirred. The world had become a vast steaming cauldron. The humid air refused to allow sweat its escape; heat raged within every organ.
Perhaps southerners from Lingnan, or the camel-riding merchants of the western sands, could endure such heat. But for the Jurchens, it was unbearable.
— Many who had been vigorous warriors only yesterday now lay prostrate in the heat, unable to rise.
And those who perished outright from sunstroke or dehydration? Their number defied count.
Even the western army's commander, Wanyan Zonghan, had succumbed. Wounds suffered in Hebei and Hedong had yet to heal, and now the heat inflamed his condition. He collapsed anew. Though captured Song physicians administered decoctions by the bowl, nothing seemed to quell the raging internal fire.
To adapt these northern men to southern heat was like asking polar bears to dwell in the tropics.
With soldiers and horses alike collapsing, the Jin army was forced to halt its siege. The afternoon of the heat's onset, they had attempted one last assault — but barely had their troops marched a few steps when half fainted in the heat. Even their steeds and oxen refused to move. They had no choice but to sound retreat.
Since then, the Jin had mounted no further attack.
Rising wearily, Zongwang washed himself and eyed the sumptuous breakfast before him without appetite. The heat was so fierce he could hardly bear his clothes — stripped to the waist, he gulped down bowl after bowl of cool water before he found relief.
Alas, his respite was short-lived.
"...My lord," came the report, "over a thousand horses have taken ill. The army's veterinarians remain at a loss."
— This hellish heatwave had not only laid waste to warriors of every ethnicity — Jurchen, Bohai, Mongol, and even the recently surrendered Han — but also to their prized steeds. Contrary to popular belief, warhorses were delicate creatures — prone to digestive upset and illness from the slightest mistreatment. Each rider's bond with his horse was a sacred charge.
But no amount of horsemanship could guard against a sixty-degree spike in temperature.
The Jin horses fell by the hundreds — stricken, fevered, and dying — leaving their riders to grieve bitterly.
Worse still, bodies littered the battlefield — human and beast alike — left unburied. When the cold held sway, decay was forestalled. But now, with the sudden surge of heat, rot and stench spread unchecked, and plague soon followed.
With a heavy sigh, Zongwang dismissed the messenger, his gaze drifting toward the blinding light outside his tent. Thoughtful silence overtook him.
— This second southern campaign, though rich in plunder, had driven the Jin army to exhaustion.
In recent days they had seen unnatural wonders — Song soldiers hurling boulders carved with words, and now this abrupt turn of season. Though he had summoned shamans and monks alike, none could offer answers for the upheaval of heaven and earth.
In such unbearable heat, even the smallest effort brought labored breath and torrents of sweat. No man could wage war in these conditions.
Disease spread swiftly. Morale plummeted.
By all accounts, Bianjing would not fall. It was time to consider withdrawal.
Yet they had conquered Hedong and Hebei, cut off reinforcements to the west, and seized Luoyang. One final push would have destroyed the Song. To halt now was galling.
And to return empty-handed would invite scorn at home. Thus, they must at least extort some tribute — gold, silk, anything to mark the campaign's "success."
But the Song now hid within their mighty walls, and the sweltering heat made any further assault suicidal. What to do?
As he pondered, sweat dripping, his mind clouded, a sudden commotion erupted outside his tent.
"What now?" he growled. "Another mishap?"
Storming out, he followed the clamor toward the direction of the city — only to see, to his utter shock, the great East Water Gate of Bianjing creaking open from within!
The proud Jin army, laid low by heat, had become sickly and sluggish. Meanwhile, the Song troops — more resilient in this southern climate — saw their chance.
The long-restrained defenders now surged forth, their banners unfurled, war drums booming. From the gate burst rank upon rank of elite troops — spears bristling, bows drawn, cavalry flanking — a grand square formation stormed the field.
Arrows rained like a monsoon from trebuchets and divine-bow ballistae.
"Curses!" roared Zongwang, swiping away a whistling shaft with his blade as he rushed forward.
— Caught off guard, the Jin front lines were thrown into disarray. The heat-crippled soldiers and scattered auxiliaries were slaughtered like sheep.
But the Song's dream of an instant victory quickly faded — for the Jin, though disoriented, were no ordinary foes. Battle-hardened and ruthless, they rallied. What began as a rout became a mire. The Song attackers, too few in number, found themselves isolated — pockets of resistance lost among the rising tide of Jin counterattacks.
A bitter stalemate followed. Under the sun's merciless glare, men from both sides fell like wheat before a scythe — either to blade or to heat.
The battlefield burned. The siege was broken. But no one emerged unscathed.