A tavern in the Subura district.
The mouth-watering aroma of roast duck and wine hung heavy in the air. Meanwhile, the hall echoed with the boisterous laughter of men.
"Those Judeans are so poor, even the god looking after them is a loner! Only one!"
"Hahaha!"
"So, if that Yahweh fellow and our Great Jupiter squared off, who'd actually win?"
"No matter how much of a god you are, numbers always win! Just look at how many gods we Romans have protecting us!"
Merchants, artisans, and laborers—all washing away the grime of a hard day's work—laughed and swapped stories while drenching their throats in wine.
Between them, Syrian slave girls, known as Syriscae, scurried about, delivering endless rounds of meat and spirits.
A young man sat alone at a corner table.
"Hey, a cup of wine here. Mix it half-and-half with seawater."
"Yes, sir. Just a moment."
The young man's name was Vitruvius. Like the others, he had come to the tavern to unwind.
Up until last week, he had been studying abroad in Greece. Now back in Rome, he found himself struggling to find a decent job.
"Perhaps I'll find an opening in Hispania." He muttered to himself.
He was planning to leave for the province of Hispania, where development was currently in full swing. Provinces always had a hunger for architects and engineers. There was bound to be a place for him there.
"Here is your wine, sir. Is there anything else you need?"
A red-haired Syrisca approached and handed him the cup. She seemed to take a liking to him, lingering with a sultry gaze intended to entice. But Vitruvius simply gave a noncommittal shrug.
"Thanks. This will be all."
Ignoring her disappointed pout, Vitruvius took a sip. The brininess of the seawater mingled with the bouquet of the wine, creating a unique, sharp flavor. Just as he tilted his cup again, a loud voice caught his ear.
"Throw any calculation at me! I'll solve it in under ten seconds!"
"Any number at all?"
"I don't care how big it is! Try me!"
"This guy's been working in insurance all day and finally lost his mind."
"You don't believe me? Then let's make it a wager! I bet I can solve any calculation you shout out in ten seconds flat!"
"Tch, if you're that eager to hand over your money, be my guest. Fine! You're on!"
Vitruvius turned toward the noise. His eyes fell upon two Egyptians, clearly intoxicated, shouting at one another.
'Preposterous,' Vitruvius thought.
Having studied mathematics in Greece, he was quite confident in his own skills.
Yet even he struggled when the numbers climbed past a hundred. To claim one could solve any calculation in ten seconds was clearly the drunken rambling of a fool.
And yet, an uncontrollable curiosity gnawed at him.
If that man truly could calculate that fast... then he had to be the greatest genius in all of Rome.
"Five asses says you can't get the answer in ten seconds!"
"Good! Let's see what you've got!"
"I'll start the count. Try to solve this in ten!" The challenger paused, thinking hard. "Thirty-four thousand five hundred sixty-seven times one hundred and one!"
The bald Egyptian sitting opposite him immediately began scribbling on a clay tablet.
His own curiosity piqued, Vitruvius pulled a tablet from his tunic.
But just as he started to etch the first digits with his stylus, the bald man's shout rang out.
"Three million four hundred ninety-one thousand two hundred sixty-seven! The answer is three million four hundred ninety-one thousand two hundred sixty-seven!"
"No way! You're lying because you think I'm too drunk to check!" his companion yelled in disbelief.
He, like Vitruvius, had barely finished writing down the initial numbers.
"If you're so suspicious, calculate it yourself. I can wait all night."
Vitruvius scribbled furiously. As the numbers climbed into the tens of thousands, the Roman numeral notation became a tangle of numerals. After nearly ten minutes of careful work, he finally arrived at the result.
The answer was, remarkably, three million four hundred ninety-one thousand two hundred sixty-seven. It was exactly what the bald Egyptian had claimed.
"Unbelievable!" Vitruvius blurted out.
The patrons nearby gave him odd looks, but he didn't care. He was more shocked than he had ever been in his life. He had never encountered anyone who could solve an equation that quickly.
The other Egyptian, having finished his own tally, cried out in shock. "It's impossible! Three million four hundred ninety-one thousand two hundred sixty-seven... wait, no, it's exactly right!"
"Didn't I tell you? The five asses are mine."
"Wait! How?! How could you possibly calculate that so fast?"
Vitruvius pricked up his ears, waiting for the answer. He might just learn a new mathematical truth in this very tavern.
"I'm only telling you this because we're friends... but you have to keep it a secret. Not a word."
"Of course! Don't you trust me?"
"The truth is..." The Egyptian glanced around before whispering in a low voice. Vitruvius looked away, pretending to focus on his wine. "The truth is, our boss devised a new number system and taught it to the staff."
"A new number system?"
"As you just saw, they're magical symbols. They let you solve any calculation, regardless of the digits, in mere seconds."
"And who is this boss of yours...?"
"None other than Lucius Julius Caesar."
Lucius Julius Caesar.
Vitruvius etched the name into his mind. He recalled hearing that the newly appointed governor of Hispania was also named Caesar.
If this wasn't a dream, he had to find out everything he could about this secret 'new number system.'
A moment later, the two Egyptians left the tavern. Vitruvius stood up immediately, waving to catch the servant's attention.
"Check, please!"
***
The next morning, before the sun had even fully cleared the horizon, Vitruvius headed for the Subura district.
"Pardon me, I'm looking for directions."
"Where to?"
"I heard Lucius Caesar runs an insurance business near here."
"Ah, you mean young Caesar. Just head over that hill and keep going straight." The passerby pointed toward a slope. "You'll recognize it immediately. There's always a crowd."
"Thank you."
Following the directions provided by the locals, Vitruvius finally reached the building.
The passerby hadn't been exaggerating. The front of the structure was packed with people even at this early hour. If not for the sign that read 'Caesar Insurance' in Latin, he would have mistaken it for the heart of a bustling marketplace.
'Good heavens, are all these people here to sign up for this "insurance"?'
Vitruvius marveled at the sheer size of the crowd. A system where you pay a set amount in advance to receive compensation in the event of a fire—it was certainly a brilliant way to hedge against future risks.
He found himself thinking it would be a loss not to sign up.
But his goal today was different. He was here to uncover the 'new numbers' he'd heard of yesterday.
If a system existed that allowed such rapid calculation, Vitruvius was willing to pay a fortune to learn it.
As he tried to enter the Insula building, those waiting in line shouted at him irritably.
"Hey! Don't you see the line? If you're here for insurance, get to the back!"
"No, I'm not here for insurance, I'm—"
Vitruvius caught the sharp glares of the crowd, sighed, and trudged to the very end of the line.
It took nearly an hour of waiting before he finally stepped inside.
"Customer number three! Please proceed to table ten!"
"Customer number eleven! If you are not present, we will move to the next!"
"I'm here! I'm number eleven!"
"This way, please."
The interior was just as packed as the street.
On one side were several tables staffed by clerks; on the other, long benches for waiting customers.
'I've never seen anything like this.'
As an architect, Vitruvius had designed several shop buildings, but this internal layout was a revelation.
Even at the public grain distributions, which handled tens of thousands of citizens a month, people were forced to stand outside in chaotic lines for hours.
Most government offices were no better than disorganized bazaars. But this place was different. Receive a number at the entrance, wait in a designated area—there was no wasted movement.
It was an incredibly efficient design. The citizens inside seemed to take it for granted, but as an architect, Vitruvius was floored. Just then, a clerk in a simple tunic approached and handed him a wooden slab with a number on it.
"Are you here to sign up for insurance?"
"No. I am here to see the owner, Lucius Julius Caesar."
"The Boss? May I ask your name?"
"Vitruvius."
"Are you an acquaintance of his?"
Vitruvius shook his head. "I am not."
"Then may I ask the purpose of your visit?"
It was only then that Vitruvius realized he had come here without a proper plan.
He had assumed an insurance company would be like any other shop. He felt his face heat up in embarrassment.
After a moment's hesitation, he answered cautiously.
"I... I heard rumors of a new number system. I came to verify them."
"The numbers? Ah, I see. This way, please."
The clerk offered a knowing smile.
As Vitruvius climbed the stairs to the second floor, he flinched instinctively. The waiting room and the hallway were already filled with people.
"Please wait here."
Once the clerk left, Vitruvius looked around. Why were all these people here to see Lucius Caesar? Just as he was about to ask, a pot-bellied man sitting next to him spoke up.
"You here to learn the new numbers, too?"
"How did you—?!"
"We're all here because of the rumors," the man replied with a laugh, having anticipated the reaction. "Some heard it in a tavern, others at the Forum. We all ended up here." The man leaned in closer and added, "I suspect we've all walked into a trap."
Vitruvius swallowed hard. Was the conversation between the two Egyptians he overheard yesterday a setup? Spreading rumors to gather everyone in Rome interested in mathematics... what could possibly be gained from that?
"What exactly is Lucius Caesar's objective?"
As he muttered the question, the door at the end of the hallway swung wide. A young man stepped out.
No, calling him a young man was generous—he looked barely more than a boy.
"To all of you who have come to uncover the new numbers... welcome to Caesar Insurance."
He spread his arms wide, looking over the bewildered guests. The pot-bellied man stood up abruptly, his voice rising.
"Caesar! We appreciate the hospitality, but I must ask: why spread false rumors about these new numbers?"
"False?" The young Caesar tilted his head, his tone perfectly calm. He looked as though he genuinely didn't understand the accusation.
"Seeing how many of us are gathered here, it's clear you ordered your staff to spread those stories, didn't you?"
The others in the hallway nodded in agreement.
"The rumors are true," Lucius said, scanning the crowd. Slowly, his gaze sharpened with an intensity that seemed impossible for a boy his age—it was the look of a predator. He unfurled a scroll of papyrus, revealing bizarre symbols he had never seen before.
0, 1, 2, 3, 4, 5...
"Today, you have all received an invitation to redesign Rome—no, the whole world. From this moment on, only those who can solve the problems I present will earn the right to learn the numbers of the gods. Now... "
Lucius grinned.
"Shall we begin the test?"