"…While I was away, another death occurred?"
"Yes."
"Miss Nightingale, how many have died so far?"
"Five. All of them patients who suffered from severe diarrhea."
After reviewing the list of patients brought to Victoria Hospital, John Snow let out a deep sigh and tossed his coat onto the desk.
"As the authorities feared, this is cholera. The symptoms are chillingly identical to the outbreak we saw before."
"Just as His Highness said."
Florence Nightingale examined John Snow's face. He looked noticeably exhausted, as though he had just returned from somewhere.
When Killian had given John Snow full authority to eradicate cholera, she had assumed Snow already knew how to eliminate it.
Logically speaking, why else would someone like Killian place such absolute trust in him?
But now it seemed that John Snow himself did not actually know the precise cause of cholera.
He was merely certain that the miasma theory, regarded as orthodoxy in the medical world, was wrong.
If Snow turned out to be completely mistaken, would it not damage the reputation of Prince Consort Killian as well?
In truth, Florence Nightingale herself had not yet fully accepted Snow's theory rejecting miasma.
If she still had doubts despite attending his lectures, how much more skeptical would other experts be?
At that very moment, London's health authorities were digging through the garbage in the slums and throwing it all into the River Thames, claiming they were purifying the city's air.
If cholera truly spread through foul air, then such measures should have shown some effect.
But just as John Snow had predicted, the epidemic showed no sign of slowing.
"Nightingale, do you still believe the miasma theory might be correct?"
"No. Of course illness may spread through foul smells, but cholera at least doesn't seem to spread through odor."
"Exactly. Cholera certainly isn't spread by foul smells. Otherwise the outbreak would already be declining. So I went out myself and conducted an investigation. Would you take a look at this?"
Snow spread a large map of London across the desk.
The map showed streets and residential districts.
At first glance it looked ordinary, but Nightingale soon noticed the black bars marked across certain areas.
"What are these black marks on the map?"
"They represent patients known to have contracted cholera. I had very little time, so I only marked them roughly. But even so, you can clearly see how they cluster in one particular area."
"Soho Street… Could it simply be because it's a filthy district with many poor residents?"
"No. It's true that many laborers live in Soho, but there are districts on the outskirts of the city in far worse condition. Yet the disease is concentrated here. That suggests a cause different from what the authorities claim."
"Professor, then do you have a suspected source?"
"I do… although…"
Snow hesitated.
Nightingale blinked.
If the cause had been identified, shouldn't they already be preparing countermeasures?
More importantly, discovering the cause of cholera would be a monumental medical breakthrough.
"Professor, we should inform His Highness immediately and send word to the health authorities and the city council. What is the cause?"
"My hypothesis is that this is the most likely cause."
Snow reached into his coat.
Nightingale instinctively flinched.
Had he really brought the source of infection into the hospital?
If cholera spread inside the hospital, how could they possibly contain it?
"Professor, you shouldn't take that out here—"
"…Hm? That's just… a bottle of water?"
"Yes. The water in this bottle is probably the source of cholera. Though it's still just a hypothesis."
"You mean the water is contaminated? But it looks perfectly normal."
She examined the water through a microscope.
Nothing unusual appeared.
If something filthy were mixed inside, it should have been visible under magnification.
But it looked completely ordinary.
"There must be something extremely small in the water—something too tiny for us to see with our eyes. Invisible gases can destroy the lungs, after all. Something in water could certainly destroy the digestive system."
"…That's possible, I suppose."
Snow's theory certainly had logic behind it.
But in academia, logic alone was not enough.
It had to be proven.
Even if the water really caused cholera, they could not simply force someone else to drink it.
"Professor, I understand your reasoning. But to convince the authorities, we'll need solid evidence. A hypothesis alone will never persuade them."
"That's true. I do have an idea. But to put it into action will take considerable time… If we could mobilize a large number of people, it might even be done in a single day."
Unfortunately, they could not use the resources of the London health committee.
Even though Prince Consort Killian had promised support, he was not a medical professional.
He might not fully understand what resources were truly necessary.
"Even so, we should request assistance from His Highness. If we need manpower, we should ask him to assign—"
"What we need aren't simple laborers. We need people skilled in gathering and organizing information. Detectives would be perfect."
Even if they requested help immediately, assembling a large team would take time.
And that would mean more victims.
Still, they could not simply stand by.
Nightingale was about to send word to Buckingham Palace when she noticed a group of people entering the hospital.
At first she assumed they were emergency patients.
But one of the men at the front walked directly toward her.
"Are you Miss Florence Nightingale?"
"Yes… I am."
"We're employees of the James Detective Agency. The Royal Household contacted us and said Professor John Snow would soon be conducting a large-scale investigation. We were instructed to assist him. What tasks would you like us to perform?"
"…Pardon?"
They had not even sent their request yet.
How did they already know manpower was needed?
And how had they sent detectives, exactly the type of people Snow had just mentioned?
Florence Nightingale had certainly heard of the James Detective Agency.
They were widely considered the finest investigators and information gatherers in London—perhaps in the entire British Empire.
Could it be that Prince Consort Killian already knew the cause of cholera before John Snow did?
No… that would be impossible.
Shaking away the absurd thought, Nightingale led the detectives to John Snow.
Whatever the reason, they now had powerful assistance.
And they needed to end this crisis as quickly as possible—
To save as many Londoners as they could.
* * *
By now, the detectives should have arrived at John Snow's side at precisely the right moment.
From what Killian had learned, cholera had already caused large numbers of deaths in Britain about fifteen years earlier.
Cities such as Sunderland, Newcastle, and London had each suffered severe outbreaks, with tens of thousands of victims.
Paris had also lost tens of thousands.
And in Russia, a massive outbreak beginning the previous year had reportedly killed hundreds of thousands.
As a result, fear of cholera already ran deep in London.
Not only ambitious young politicians like Otto von Bismarck, but even Karl Marx and Friedrich Engels were watching the situation closely.
"Your Highness, newspapers are already reporting that cholera may spread throughout the city. Were you aware of this?"
"The news is already out? Journalists really do leap on any story they can."
"Cholera is no minor illness. A few years before we arrived in Paris, there was an outbreak that killed nearly one hundred thousand people."
"That's right. A terrifying disease. Few wars kill tens of thousands of people, yet cholera can produce casualties from ten thousand to a hundred thousand in a single outbreak."
"But the Morning Post says that you have declared you will suppress cholera using the medical staff of Victoria Hospital and Killian Medical College. Is that true?"
So the news had spread far enough that Karl Marx had already heard it.
The newspapers had been worth using after all.
Still, Marx's expression suggested he doubted whether Killian could truly accomplish such a thing.
Which was understandable.
After all, how could anyone believe that a young royal could halt a plague that had killed millions?
Most people would assume it was simply political rhetoric.
Unfortunately for them—
It was true.
"Yes, I said that. The medical teams are already organized, and investigators have been dispatched. We should see results within a few days."
"…That sounds as though you already know the cause of cholera."
"I do. And my medical team will likely discover it soon as well."
"You mean you knew before the doctors did? That seems… well… setting that aside, shouldn't you have told them immediately?"
"If I had, would they have believed me? Imagine a politician with no medical training walking into their offices and saying the water from a certain pump spreads cholera. Would any expert simply nod and accept it?"
Experts who have devoted their lives to a field rarely accept outside interference.
Not even from the Queen.
Even if Killian handed them the answer outright, they might reject it out of pride.
It was far better to guide John Snow and Florence Nightingale quietly from behind.
Sometimes the fastest way forward was to take the long road.
"Marx, do you know why diseases like this flourish even as technology advances and society changes?"
"…I'm not sure."
"People believed foul smells caused disease, so they removed garbage from the city and threw it where no one could see it. In cities with rivers—like London and Paris—that was easy. Just throw it into the water."
And so the Thames and the Seine became horribly polluted.
Londoners and Parisians had unknowingly created the perfect environment for cholera themselves.
"Do you think people threw garbage into the river because they wanted to become sick? Of course not. The health authorities encouraged it in the name of protecting public health. Yet the result was the worst possible outcome—cholera spreading and hundreds already dead. Do you understand my point?"
"You mean decisions believed to be the best at the time can produce the worst consequences."
"Exactly. There's a saying that the road to hell is paved with good intentions. If something clearly appears malicious, people resist it. But if it looks benevolent, they follow without question. Just as doctors, guided by the mistaken belief in miasma, tried to improve the city—only to increase cholera deaths."
Marx nodded quietly.
Killian's meaning was clear.
Just as miasma theory had worsened cholera, Marx's new ideology could also create unintended disasters.
"Ideologies and theories are fine. But never forget that the most important thing is the people living in the present. Any theory that makes real people miserable is worth no more than the garbage lying in the street."
"So that's why Your Highness built hospitals and is personally trying to solve the cholera crisis."
"Exactly. So watch carefully and refine your theories. If heaven has given you genius, use it to improve the world."
Killian checked the time.
It was almost time.
He rose and put on his coat.
"Do you have another engagement?"
"I promised to attend Parliament today."
People already understood the seriousness of the situation.
Which meant it was time to push harder.
Public health was separate from domestic politics.
Even if Killian took control, there would be no legal issue.
Before the number of victims could rise any further—
This terrible plague needed to end.