Looking back and going through the long list of scientific achievements built by the Arab Empire, Zhuge Liang found a very specific quote echoing in his mind. It was a classic line from the great sage Confucius.
"When three men walk together, one of them must surely be my teacher."
That ancient piece of wisdom summed up the Arab success story perfectly.
The geography of their empire placed them right in the center of the known world. They sat exactly on the line dividing East and West. They absorbed the biological and philosophical knowledge of ancient Rome. They eagerly picked up the mechanical engineering and manufacturing techniques of ancient China. By gathering the best ideas from two different hemispheres, they forged a powerful state that lasted for centuries.
Zhuge Liang tapped his fingers on his wooden desk. A sharp realization took clear shape in his mind. If a nation truly wanted to master the physical sciences, building schools and pushing heavy research was obviously crucial. But shutting yourself away in a library was not enough. Active and eager intellectual exchange with foreign nations was just as mandatory.
He thought of the future Ming Dynasty. The Lightscreen had already sharply criticized that specific era many times.
The Ming emperors had deliberately put in place the disastrous Sea Ban policy. They locked their ports, burned their ocean-going ships, and cut themselves off from the global trade and exchange of ideas.
Because of that arrogant isolation, their empire rotted from the inside out and was eventually crushed by foreign cannons battering down their doors. If the Ming Dynasty had simply kept their ports open and talked to the outside world, they might not have avoided total collapse in the end, but their national lifespan could certainly have stretched on for at least another full century.
Zhuge Liang shook his head, physically tossing those gloomy and useless thoughts about the distant future right out of his brain.
He needed to focus on the present.
Zhuge Liang reached for his brush without looking away from the floating panel. He dipped it in ink and started copying the six steps onto a fresh scroll, his strokes clean and sharp.
"Abstract. Explore. Doubt. Option. Practice. Guide."
Pang Tong leaned over his shoulder, squinting at the characters forming on the paper. "The future generation called this stuff a medical doctrine. Just rules for patching up sick people, right? Tell me if I am wrong, Kongming."
Zhuge Liang did not look up. His brush paused for just a heartbeat before moving again.
"Look at the sequence, Shiyuan. One step forces you to ask the next question."
He set the brush down and tapped the scroll once with a finger.
"Medicine is only the beginning. The same habit could work for engineering, farming, even government."
Pang Tong stroked his beard and nodded slowly, but his eyes still held a trace of skepticism.
"Patterns within patterns, eh? You always did see the grid behind the chaos. How do you do that? Where did I miss it?"
A loud warm laugh cut across the tent before they could say more.
Both men turned to see Zhang Zhongjing pushing himself up from his bench, his face lighting up like a kid handed a box of rare and precious herbs.
The old doctor stroked his long white beard and looked around the room, his eyes crinkling into happy little lines.
"Alright everyone, I have a confession!" Zhang Zhongjing's voice carried easily over the soft chatter of soldiers and clerks. "A pretty embarrassing one too."
Zhang Fei, who sat nearby polishing his spear, looked up and grinned. "What is it, old man? Did you sneak an extra jar of rice wine last night and forget to share? If you did that, you need to share with me right now after this."
Low chuckles rippled through the tent.
Zhang Zhongjing waved off the teasing, his smile never fading. "It is better than that, Yide. You know that. Not too long ago, when the order came to march north, I got scared. Proper scared."
The laughter slowed a little. Every eye stayed on him.
"I got too soft living in Chengdu, and the fault is all of yours, hehe." Zhang Zhongjing waved vaguely toward the south. "Warm air. Nice cozy clinic. Steady supply of every herb I could want. The thought of crossing thousands of miles of freezing mountains made me want to fake a fever and stay behind."
Zhang Fei barked out a loud laugh that shook his bench. "You? A doctor scared of a little cold weather?"
"I was!" Zhang Zhongjing laughed at himself and jabbed a finger toward the glowing Lightscreen. "But look at what we got today. Proper structured medical theory. Ways to study how the body works. A whole system of thinking from the other side of the world."
He leaned forward a little, his voice growing firmer. "This knowledge is truly precious, I can tell you that. And if getting this knowledge meant walking 5,000 miles through the worst blizzards anyone can dream up? I would tie my boots tight and start marching before anyone finished giving the order."
Warm genuine laughter rolled through the tent again. Even Zhuge Liang let a wide smile cross his face. He leaned toward Fa Zheng, who sat beside him, and spoke in a low voice.
"For a whole year, that screen has rambled on about farming and battle plans and politics. It almost never talks about the fine points of medicine. No wonder the old man feels like he just found a treasure chest left wide open for him."
Fa Zheng nodded. "Chengdu is easy living. The Sichuan basin stays mild even in winter. No one could blame him for wanting to stay in his warm clinic instead of facing the northern wind."
Zhang Zhongjing heard them and raised a hand. "This is more than just comfort. I have spent years fighting to finish my Treatise on Cold Pathogenic Diseases. This Roman method, the whole level of it, it gives direction. It fits exactly where I got stuck. It is like a long heavy rain falling on fields that have been bone dry for ten years."
Even Ma Chao, who had been listening from his seat, gave one slow solemn nod of respect.
Right in the middle of all the good cheer, a low annoyed grumble came from the far corner of the tent.
Jian Yong sat hunched on a wooden bench, his face twisted up like he had just bitten into a whole sour lemon. His arms were crossed tight over his chest, and he stared at the ground like it had personally insulted his entire family.
Liu Bei, who sat nearby, raised an eyebrow. "What has gotten into you, Xianhe? You look like you would rather be anywhere else right now."
Jian Yong huffed and looked up. "My lord, I will tell you what has gotten into me. My retirement plan."
Zhang Fei leaned forward, grinning. "Retirement plan? What, you want to open a tea shop? Or maybe a food stall?"
"It is not that!" Jian Yong waved a hand in frustration. "I have always wanted to travel. Everyone here knows it. Once our lord takes the Central Plains and brings peace to the Han Dynasty, I was going to pack my bags and head west. See the legendary Roman Empire with my own two eyes."
He jabbed a finger toward the Lightscreen. "But what does this thing tell us? Rome is drowning in the exact same mess we are living through right now. Warlords. Plague. Civil war every other year."
He threw his hands up. "If I wait for peace here, then ride a camel west, I will not be arriving for a relaxing holiday. I will walk straight out of a nice peaceful country right into a warzone. Some random gladiator could stick a knife in my ribs just for the coins in my pocket."
The tent broke into fresh laughter.
Zhang Fei slapped his knee so hard his spear rattled against the tent pole. "Then stay here! Why risk getting stabbed over some old stone buildings and bathhouses?"
"Roman bathhouses are famous!" Jian Yong shot back, clearly defensive now. "And their architecture! Their roads! Looking at the Lightscreen only makes me more curious. I want to see it all for myself before I die."
Pang Tong shook his head, still smiling. "You could always go later. Wait a few decades. Let Rome sort itself out."
"Decades?" Jian Yong groaned and slouched back against the tent pole. "I will be too old to ride a camel by then. Too old to walk around and see anything properly. I will just be some old guy sitting in a cart complaining about sore knees."
Zhuge Liang picked up his brush again and dipped it back in the ink. His eyes crinkled with amusement. "Xianhe, maybe for now you could learn a few words of their language. Prepare nice gifts. Hire capable guards. And maybe pick some who can fight off ten stray gladiators at once."
Jian Yong huffed and crossed his arms even tighter. He turned his face toward the tent wall and refused to say another word on the subject.
---
Inside the Ganlu Hall of the Tang Dynasty, ministers and generals sat arranged around Emperor Li Shimin. The Lightscreen had just finished showing the segment about Rome's climate disasters and plagues.
The air felt heavy for a moment.
Fang Xuanling let out a long heavy sigh and slumped slightly in his seat.
"The global climate shifts by just a small fraction, and centuries of imperial glory get wiped clean away."
Du Ruhui, who sat right beside him, glanced over and raised an eyebrow. "You sound like you just watched the sky fall. What is weighing on you, old friend?"
Fang Xuanling gestured vaguely toward the floating panel. "Those images of the universe they showed us earlier. I cannot get them out of my head. The vast emptiness of space. Our whole world just a small blue ball spinning in the dark."
He shook his head slowly. "The more I think about how the cosmos works, the more I realize just how small human beings really are. This broadcast only makes that feeling stronger."
A low murmur of agreement rippled through the hall. Every minister present knew the chaotic history from the late Han all the way to the rise of the Sui and Tang by heart. Watching the exact same cycle play out in distant Rome left a bitter taste in every mouth.
"We do not have exact tools to measure how far temperatures dropped back then." Fang Xuanling leaned forward slightly. "But you can see the truth plain enough in ordinary people's records. During warm golden ages, heavy snow rarely touches the northern deserts. During cold freezes, the southern rivers of Jiangdong turn solid enough to walk across."
Someone in the back huffed. "Rivers in the south turning to ice? That sounds like a bad joke told to scare children."
"It is no joke." Fang Xuanling's voice stayed steady. "If the invisible line marking the four seasons shifts south by just a hundred miles, millions of crops die. A mighty empire crumbles. A full century of blood-soaked chaos follows right after."
The hall went still for a heartbeat.
Du Ruhui reached out and gave the back of Fang Xuanling's hand a firm pat. His voice stayed gentle but carried an unshakable firmness.
"Because the world is so harsh and unforgiving, we must work even harder to shape the destiny of the Great Tang ourselves."
He squeezed his friend's hand. "Using human will and collective engineering to conquer the ancient repeating anger of the global climate. What could possibly be more glorious than that?"
Fang Xuanling blinked. His posture straightened up right away, as if someone had poured hot water down his spine. The heavy gloom on his face vanished, replaced by a spark of bold ambition.
"Glorious indeed." A low voice came from across the hall. Veteran general Qin Qiong looked up from the scrap of paper he had been scribbling on. "We followed His Majesty through a literal sea of blood to end the chaos of the Sui collapse. If we were the kind of men to give up when things look impossible, none of us would be sitting here today."
Nods of agreement moved through the seats.
Du Ruhui leaned back in his chair and smiled, a relaxed almost teasing smile.
"Besides, according to the original timeline shown on that screen, I should have been dead by now. A long running illness was supposed to take my life years ago." He tapped his own chest lightly. "Thanks to future medical knowledge, I am still breathing. I am living on extra time, operating outside the bounds of fate. I, for one, plan to use that time to change the world."
A few soft chuckles spread through the hall. The heavy mood broke completely.
Qin Qiong went right back to scribbling on his paper, muttering half to himself. "Rome's winter supply failures. Need to recalculate our own grain storage and heating material plans. Cannot let our troops freeze when the cold comes."
Beside him, aggressive commander Hou Junji licked his lips, his eyes burning with eager energy. "Why wait for the cold to come? We should march out and seize new lands now while the weather still holds. Grab more farmland, more resources, before the climate turns against us."
Someone snorted from a nearby seat. "Slow down, Hou Junji. You sound like a hungry dog spotting a piece of meat across the yard. We need plans, not just charging forward."
In the far corner, Zhangsun Wuji chewed on his lower lip, staring at his own hands.
Foolish. So foolish. I stepped down voluntarily from my prime minister post not long ago. I wanted a quieter life. But now? Now I want to be right at the helm when the Tang Dynasty conquers nature itself.
On the other side of the hall, young naval commander Liu Rengui could barely stay still in his seat. He bounced his leg up and down, eyes gleaming.
"New ships. My new ship designs. We can test them soon. Sail further, map more coastlines, secure trade routes before anything changes." He grinned wide. "This is not a problem. This is a chance."
The newly appointed top scholar Ma Zhou, by contrast, looked deadly serious. He rubbed his temples, staring at the Lightscreen as if trying to burn every geopolitical detail into his brain.
"Too much data. Too many shifting factors." He muttered under his breath. "Need to cross reference climate patterns with border stability with crop yields. This will take weeks to sort through properly."
Emperor Li Shimin sat forward in his imperial seat, watching all the energy fill the room. He let out a slow satisfied breath and spoke in a soft but clear voice that cut through the chatter.
"Stones from other hills may serve to polish the jade of this one."
The hall went still again, everyone turning to look at the throne.
"The brutal failures of the Roman Empire." Li Shimin nodded toward the screen. "They are the perfect grinding stone to sharpen the blades of the Tang Dynasty. We learn from their mistakes. We prepare where they did not."
A loud scratching sound cut through the stillness that followed.
Everyone turned to look. Sitting off to one side, the divine physician Sun Simiao paid no attention at all to the political discussion or the imperial speech. His brush flew across the paper so fast it looked like a blur. He leaned so far over his desk his nose almost touched the scroll.
"Is he even listening?" Hou Junji whispered loud enough for half the hall to hear.
Fang Xuanling chuckled softly. "He has not looked up once since the segment on Roman medical methods started. For him, all this talk of climate and empires is just background noise. The medical details are the only treasure he cares about."
Sun Simiao did not react at all. His brush never slowed. He was already too busy capturing every single detail of the Roman method to care about anything else happening in the hall.
[Lightscreen]
[The year was 249 AD. The brilliant and totally ruthless strategist Sima Yi stood on the banks of the Luo River.
He looked up at the sky and formally spat out a load of made-up solemn nonsense that changed the whole path of Chinese history.
Later generations jokingly nicknamed this episode the "Luo River Fart." Although, honestly, I suspect Prime Minister Zhuge Liang would have thought that name was way too polite. Right?
Sima Yi swore a sacred unbreakable oath to the heavens that he would not harm the ruling Cao family if they surrendered. He swore it on the flowing waters of the river itself.
The Cao family bought it. They laid down their arms.
Sima Yi immediately broke his oh so sacred oath and slaughtered every last member of their extended family.
Thanks to this legendary act of backstabbing, the state of Wei, which had the strongest military and economy of all Three Kingdoms, basically became the very first faction to get permanently wiped off the board.
The Sima family stole the whole empire right out from under their noses.
In that exact same year, on the opposite side of the globe, the chaotic Roman Empire was busy drowning in its own Thirty Tyrants crisis.
And right on schedule, a second apocalyptic epidemic popped into existence.
This biological nightmare burned through the Roman population for sixteen horrifying years. It easily killed hundreds of thousands of people and kicked the already wobbly foundations of the empire even harder.
Because the political situation in Rome was a total mess full of rogue warlords, the official government bureaucracy had basically stopped working entirely. The secular state gave up keeping any records at all.
The most complete and horrifyingly detailed written accounts of this plague were saved by a guy named Cyprian, who served as the Christian Bishop of Carthage.
Thanks to his very thorough note taking, modern historians officially call this disaster the Plague of Cyprian.
Looking at the Bishop's surviving records, this new plague shared a weird similarity with the typhoid epidemics tearing through the Han Dynasty.
It followed a super clear seasonal pattern. Infection rates would blow up in autumn, fade slowly during the scorching summer heat, then bounce right back the second the weather turned cold.
It was a never ending repeating nightmare.
Epidemiologists today think this specific disease also started deep in the regions of Central Asia. It hitched rides with desperate refugees running away from warfare, spreading slowly toward cities along the Mediterranean coast.
After jumping from town to town for roughly three years, the virus finally got a solid foothold inside the Roman Empire and started multiplying like crazy.
Locking down an exact and verifiable death toll for this ancient disaster is basically impossible. We simply do not have the fancy spreadsheets.
We do have one record from a panicked scholar living in Athens. He loudly claimed that at the peak of the mess, the city of Rome lost at least 5,000 citizens every single day.
Now you usually have to treat ancient statistics like that as nothing more than made up gossip. Mostly because this exact same Athenian scholar also wrote down his firm belief that the plague spread through two main ways.
Unwashed clothing.
And making direct eye contact with a sick person.
Yeah. Direct eye contact.
However, we can cross check that daily death number with much more reliable and boring administrative data. We can look at municipal reports filed by the Bishop of Alexandria.
The Bishop carefully wrote down the exact number of people getting daily public food rations before the plague hit and the number of people getting rations after the plague burned itself out.
If you do the basic math on the Bishop's food distribution numbers, the result is chilling.
The permanent population of the city of Alexandria dropped by a staggering 62 percent.
Even if you count the thousands of rich citizens who simply packed their bags and ran to the countryside to escape the sickness, that population drop is still absolutely catastrophic.
So 5,000 dead a day in the capital city? It might be a little overstated, but it definitely sits very close to the real level of horror.
What is more, Christian bishops across the empire stepped in to act as temporary doctors. They recorded the physical symptoms of the dying with disturbing clinical precision.
They noted spikes in body temperature. Severe bloody stool. Muscle failure. Lesions rotting away the esophagus. Violent vomiting of blood. Gangrene destroying limbs.
And if a patient somehow lived long enough to reach the late stages of infection, the virus often caused permanent deafness and blindness.
Based on these specific gruesome historical clues, modern scientists have narrowed the identity of the Cyprian Plague down to two likely suspects.
Suspect number one is an aggressive strain of Influenza. We all know how the flu works. It is still hanging around today mutating and causing trouble. No extra explanation needed.
Suspect number two is way more terrifying. A Filovirus. To put that in simple terms for everyone, the most famous member of the Filovirus family is Ebola.
Honestly, looking at the symptoms, the hemorrhagic Filovirus theory makes way more sense.
These specific viruses usually go through an unseen incubation period of five to ten days. A person catches the virus but feels totally fine for a week before their organs suddenly start failing.
The idea of an unseen incubation period was impossible for ancient people to wrap their heads around.
Whether you lived in Rome or China, ancient medical theory relied on immediate cause and effect.
If a guy walks around looking perfectly healthy then suddenly starts bleeding from his eyes, ancient peasants naturally assume a demon put a curse on him, or that he caught the disease by looking at someone the wrong way.
Makes total sense, right?
There was one tragic difference between this plague and the earlier Antonine outbreak in Rome.
During the first plague, the doctor Galen had stepped forward, conducted autopsies, and tried to fight back with actual science.
During the Cyprian Plague, there was no Galen. The scientific community ran completely out of ideas. Doctors threw their hands up in total defeat.
And because science failed, both the East and the West ultimately ended up at the exact same historical destination.
When the secular government abandons starving peasants and professional doctors admit they cannot stop the bleeding, desperate masses turn to the only people left offering any kind of comfort.
They turn to religion.
If you look at original sources from this era, the fact that all the best medical records were written by Christian Bishops tells you everything you need to know about who actually ran the relief efforts.
Roman governors ran for the hills. The priests stayed and fed the sick.
Therefore, it is an undeniable historical fact. These horrific world ending plagues acted as the most effective accelerators for the eventual total domination of the Church over the western world.]