When someone contracts cholera or severe dysentery, the body expels fluids at a terrifying rate.
Dehydration is what kills them.
Strictly speaking, it is not the bacteria alone that takes their lives—but the body's reaction to it.
And the solution?
Simple.
Oral rehydration therapy.
Water mixed with precise amounts of salt and sugar to match the body's natural fluids—administered continuously.
No injections. No complex instruments.
Just a solution that allows the body to endure dehydration long enough to recover.
If I remembered correctly, this method was only widely recognized in the late twentieth century.
"And you say plain water is not enough?" Garnier asked, frowning.
How do I explain osmotic balance to a twelfth-century knight?
I couldn't simply say, "I know because I'm from the future."
I forced my thoughts into something plausible.
"I once read of a treatment in a Greek medical text. It was said to be highly effective for patients suffering such symptoms."
That should suffice.
Garnier looked thoughtful.
I approached one of the water containers beside a patient's bed.
As expected—plain water.
"What are you doing?"
The question came sharply.
A boy carrying buckets stared at me, irritated. His skin was darker than most Europeans here, his hair cropped short.
Turk? Arab?
He sighed heavily.
"We are busy. If you are merely curious, stand aside."
"Mind your tongue, Aig! Do you know who—"
I raised a hand to stop Garnier.
We did not have time for wounded pride.
"Prepare the cleanest water you can," I said. "Better yet—boil it first. And bring sugar and salt."
"Sugar and salt?"
I nodded.
Now, the proportions…
I recalled a lecture faintly.
'If the osmotic concentration is too high, it may draw water out of the body instead. But properly balanced oral rehydration does not cause imbalance. It restores fluids efficiently—even during battle.'
Better to begin cautiously.
Monks and attendants gathered around.
"I will assist."
"Bring more vessels!"
Despite the strange order, they obeyed without hesitation.
Royalty had its advantages.
If a beggar had said the same, he would have been ignored.
Within minutes, the first mixture was ready.
"Begin with children and the elderly," I instructed. "Small sips every five minutes. Even if they vomit, continue."
The effect was swift.
Within hours, many of the most severely dehydrated patients began regaining strength.
"We need more here!"
"Fetch more salt! Not bowls—bring sacks!"
Once they saw the results, the monks and knights moved frantically.
I joined them.
As we boiled more water and added the mixture, Garnier leaned close.
"Your Highness… did that Greek text mention anything else? If you could name the volume—"
"I will search for it upon returning to the palace. For now…"
I glanced around.
Beds crammed too closely together.
Filthy blankets.
Instruments reused without washing.
You didn't need modern medicine to know this was a disaster.
"This place requires more than one remedy," I muttered.
The work continued for three days.
It became an impromptu hospital reform.
I had changed nothing revolutionary.
Frequent cleaning.Washing tools with clean water.Changing linens.Separating patients when possible.
Basic hygiene.
To me, it was obvious.
To them, it was novel.
And the results were undeniable.
Patients improved daily.
"I have worked aboard ships for months," one man told me weakly. "The physicians bled me again and again, but it did nothing."
"Months at sea?" I asked. "Are your gums bleeding? Do your teeth feel loose?"
"Yes…"
"When did you last eat fresh fruit?"
He stared blankly.
"Bring him lemons. Or limes. He must eat them, whether he wishes to or not."
Scurvy.
At least that was easy.
I hadn't expected to play physician in medieval Jerusalem.
"Your Highness, there you are," Garnier called. "Lady Sibylla has come."
…Of course she has.
I washed my face quickly and headed to the central hall.
I already knew why.
I had vanished from the palace for days.
The number of vomiting patients had dropped dramatically.
The solution did not cure the illness itself.
But it prevented death.
And sometimes that was enough.
"Baldwin!"
My mother's voice rang out.
She was still radiant.
Though her stern glare dampened the effect.
"You disappeared from the palace for days without a word. What were you thinking?"
"I apologize, Mother."
"There are ways to help without causing your family to fear for you."
There it was.
Concern.
I smiled faintly.
At least in this world, someone worried for me.
"There was much to be done here."
"That you would volunteer to work in such a place…" She trailed off.
"You seem suddenly grown."
"All boys become men eventually, Sibylla," another voice said.
I turned.
Brown hair. Chainmail. Red cloak. Sculpted face and mustache.
Guy of Lusignan.
My stepfather.
Future king of Jerusalem.
And the man who would lead the army to disaster at Hattin.
"You look healthy enough for someone hiding in a hospice," he said with a smile.
I returned the look evenly.
"You train with the Hospitallers now, I hear. Do you intend to join their order?"
"That is enough, Guy."
He laughed lightly, hands raised.
There was tension between them.
Interesting.
"I hear you wish to travel to Eila personally," he continued. "You should reconsider. You are still young."
"And Jerusalem's soldiers are not toys to be moved for childish whims."
Ah.
So that was his angle.
"Thank you for your concern," I replied calmly.
Then I stepped closer.
"And you, perhaps, should reconsider withdrawing coin from the royal treasury."
His expression froze.
Shock.
Panic.
"…What did you say?"
"You know precisely what I mean."
His secret was no secret to me.
In-game, uncovering Guy's financial manipulation was a standard intrigue path.
He had been buying support.
Preparing for the throne.
"I trust you will support your stepson," I said pleasantly.
Silence.
Finally, he exhaled sharply.
"Eila lies near the lands of Reynald," he said. "A friend of mine. I shall write him."
"Much appreciated."
Reynald of Châtillon.
The kingdom's loose cannon.
I intended to deal with him anyway.
Sibylla returned.
"They speak highly of you here, Baldwin. I do not fully understand this 'solution' of yours—but you have done something remarkable."
She smiled.
"Now come. His Majesty requests you."
I nodded.
Perhaps my [Ill-Mannered Rake] trait was fading.
As we departed, monks and knights bowed and thanked me.
It felt… strange.
But not unpleasant.
As we rode back toward the palace, Sibylla leaned closer.
"If you have changed your mind about Eila…"
"I have not."
Guy remained silent, watching me.
"Then I shall instruct Treasurer Guillaume to release funds for your journey."
"Thank you, Mother."
I smiled.
Then added softly—
"There is something you must know."
Guy would attempt to control the throne—through force or manipulation.
That had to be prevented.
And I intended to begin now.
__________________________________________________________________________________________________________
Q: Was oral rehydration truly that effective?A: According to WHO and UNICEF, oral rehydration solution reduced global under-five deaths from diarrheal disease by over 75% between 1980 and 2008. In the 12th century, where hygiene was minimal, its impact would have been even more dramatic.
Q: Wasn't sugar extremely expensive at the time?A: Sugarcane cultivation and sugar refining were already present in Crusader territories such as the Jordan Valley, Tyre, and Acre. Honey was also a major local product of Jerusalem and widely available.