Incredulous eyes turned toward the young boy. Some, their voices broken with panic, asked again and again if he really believed he had found a solution. Their words echoed in the air thick with anxiety:
"Are you... are you sure?"
"It's not possible... do you really think we can get out of this?" "
The boy nodded solemnly. His voice, though still young, carried an unexpected assurance:
"I have an idea. But for it to work, everyone will have to follow my instructions."
A heavy silence fell, broken only by the muffled coughs of those who were already beginning to weaken from the toxic gas. Everyone exchanged glances with their neighbors, and it became clear that there was no other solution. No one else had the perspective or the clear mind to come up with a plan. It didn't matter that he was just a teenager: he was their only hope.
Without a word of protest, the crowd bowed to his will. The boy stood up slightly straighter, his features marked by concentration. "Reo," as he called himself, took a deep breath before declaring:
"We will form three groups. Each group will analyze one of the three tunnels. Observe everything, every inscription, every detail. If anything seems suspicious, make a note of it. Every piece of information could be vital."
A shiver ran through the crowd. Men, women, young people, all organized themselves in silence, ready to follow these orders without question. They had not chosen Reo: fear and the lack of alternatives had imposed him as their guide. And in this chaos, where no one knew how to survive, everyone preferred to rely on him rather than sink alone into the inevitable.
The two groups assigned to tunnels 2 and 3 quickly dispersed, disappearing into the thick toxic fog that already darkened the streets of the Ariake district. They scanned the walls, scrutinized the ground, lingered over every crack, every mark engraved in the stone or inscribed on a sign, but despite their best efforts, nothing seemed to offer them the slightest clue. Time passed, oppressively, and every minute that went by without a clue only increased their distress.
One of the men, his eyes reddened by the gas and panic, finally whispered, clenching his fists:
"What if that kid didn't understand anything at all? He's still young, how can he know better than us? Maybe he's just improvising to give us a little hope..."
His words echoed in the heavy silence that followed. A few nodded in agreement, fear gaining ground in their eyes. But one woman shook her head bitterly:
"Do you think we have a choice? Whatever happens, we can't do any better than him. We haven't found anything, we don't have any other solutions..."
Another added, his voice trembling:
"Maybe he's wrong... maybe he's condemning us all. But at least he's trying. And I'd rather try something than die doing nothing."
Silence fell once more, punctuated only by heavy breathing and coughing fits. Doubts hung heavy in the air, but deep down, they all knew they had no choice but to follow Reo, the boy who, despite himself, carried the weight of their lives.
The man who had expressed his doubts kept his arms crossed, refusing to give in to the general appeasement. His voice, laden with a mixture of anger and contempt, rose again:
"Kids these days... always trying to act like adults. They think they understand everything about life when they haven't seen anything yet. This Reo guy, he may think he's saving us, but he has no idea what it's like to bear real responsibility. In real life, it's not a game... and he knows nothing about it."
A few heads turned toward him, hesitant. Fear made his words more audible, as if they echoed the unspoken thoughts of some. However, another man, more composed, finally replied, shaking his head:
"You're exaggerating. We shouldn't underestimate him either. Look around you... do you think we're so easily fooled? If he tries anything, we'll be the first to react. We won't let ourselves be manipulated by a child, you can be sure of that."
This remark, almost reassuring, seemed to calm the tensions a little. The man with his arms crossed relaxed slightly, as if he had regained some form of control by imagining that they still had the upper hand. His breathing became less ragged, his shoulders less rigid.
It was then that one of the members of the group, who had remained silent until then, made an interesting remark.
Reo stepped forward toward the two groups, who were returning looking tired, their faces marked by worry and the first effects of the gas. His gaze, sharp and focused, lingered on each of them before he asked in a clear voice:
"Are you sure about what you're saying?"
The two groups exchanged glances, then replied in unison, as if to dispel any doubt:
"It's unequivocal. The oxygen consumption of the masks is the same in each of the tunnels."
A silence followed by a slight murmur ran through the assembly. Many saw it as an insignificant detail, but for Reo, this information was crucial. His eyes widened slightly, a spark of certainty crossing his face.
He had just understood.
The clue, until then drowned in collective anxiety, revealed itself to him with relentless mathematical clarity. If the consumption of the masks was identical, then the real key was not in the object itself, but in what it allowed them to pass through. Reo had already made the connection: all he had to do was calculate the volume of each tunnel to determine which one was actually passable with the limited oxygen.
A slight, almost imperceptible smile appeared on his lips. For him, it was obvious. Where others saw a macabre game of chance, he saw logic, an equation to be solved. It wasn't luck that would decide their survival, but the rigor of mathematics.
Reo, a student with a passion for numbers and a specialization in mathematics, was now certain that he held the solution to the puzzle in his hands.
While it all seemed crystal clear to Reo, this was not the case for everyone. Many remained frozen in fear, unable to grasp the logic behind his words. It was then that a group of four people approached him, immediately attracting the worried glances of the crowd.
Their appearance commanded silence. Worn cargo pants, chains jingling with every step, bodies covered in aggressive tattoos, piercings glinting in the blue light of the virtual window... Their mere presence was enough to frighten the others, who instinctively moved out of their way.
The leader of the group, more charismatic than the others, with a scar across his eyebrow, approached Reo with heavy steps. He stood right in front of him, a smirk on his lips, and said in a deep, defiant voice:
"Listen, kid... your math jargon might impress others. But we don't understand a word of it. So you're going to explain it to us clearly, in simple terms, because right now... we don't get it."
Behind him, his friends burst out laughing, mocking him loudly, their snickers echoing like a provocation. They high-fived each other, as if the general distress were nothing more than entertaining spectacle. But in their eyes, a spark of curiosity betrayed that they still wanted to understand what Reo really had in mind.
Reo was not intimidated by the piercing stares or the snickers around him. He took a calm breath and then resumed his explanation with confidence, his clear voice contrasting with the chaos around him.
"The oxygen consumption of the masks is the same for each tunnel, exactly 13,500 units of O₂." He paused, letting the information sink in. "Therefore, we simply need to calculate the volume of each tunnel. The one whose volume best matches this consumption will be the right passage to choose. It's purely logical, nothing to do with luck."
A long "ah" escaped from the mouth of the group leader, like the growl of a beast slowly digesting the idea. He narrowed his eyes, a half-smile playing on his lips:
"Are you telling me we can really calculate this kind of thing?"
Reo nodded without hesitation:
"Yes. It's possible. And it's the only way to avoid dying here."
The leader stared at him for a moment, then looked away slightly, as if to hide his impression. His companions burst out laughing again, but this time their laughter sounded more nervous, less mocking than before. One of them finally fell silent abruptly, his eyes darting between Reo and the chief, while another stopped smiling, looking more serious. Only the last one continued to snicker, unable to break his mask of defiance, as if he refused to admit that a mere "kid" could be right.
The leader shrugged before turning on his heel, throwing over his shoulder:
"All right, kid. When you're done with your math stuff... just come tell me which tunnel to take. I've got other things to take care of."
After this scene, a slight commotion rippled through the crowd. Reo's words, though logical, had sown doubt in some minds. Several people approached him, looking skeptical and almost accusatory.
One of them spoke up in a confident voice:
"You know very well that it's impossible to calculate the volume of the tunnels. They're not even real tunnels, just alleys that look like them."
Murmurs of approval could be heard among the crowd, heightening the tension. Reo crossed his arms, unperturbed, and calmly admitted:
"You're right, they're not real tunnels. They are indeed streets."
A brief silence fell, as if the admission confirmed the skeptics' doubts. But Reo immediately continued, his voice regaining its firmness:
"However, look closely above each of these alleys. "
He pointed upward, drawing attention to a detail that most had not taken the time to analyze. There, rising above the streets, were translucent barriers, each tinged with a different color, stretching upward to form veritable vaults. These structures, imperceptible at first glance, came together to create the perfect illusion of enclosed tunnels.
"It is these dimensional barriers," explained Reo, "that give these alleys the shape of tunnels. And it is precisely because of them that volume calculation is possible. Without them, you would be right: they would be just ordinary streets. But here, the rules are different. "
A shiver ran through the audience, oscillating between incomprehension and wonder, as if they had just discovered a new hidden piece in the puzzle of the enigma.
Reo continued calmly, demonstrating his keen sense of observation. He raised his hand to a sign attached to one side of the alleyway.
"Take a good look at this number," he said in a confident voice. "Many people think it's just a timer... but I'm convinced that it actually represents the distance to the safe zone."
A murmur ran through the crowd. Some were beginning to understand the boy's logic. Reo continued:
"If we already have the length, all we have to do is determine the width. And I can calculate that myself, using my steps as a unit of measurement."
A slight sense of relief spread among those listening to him, but suddenly a voice rose from the crowd:
"What about the height?" asked a man, visibly skeptical.
Reo paused. His gaze fixed on the translucent barriers that formed the vault above their heads. Then, in a sincere but firm tone, he replied:
"The height... that's another story. I have no way of calculating it accurately."
A heavy silence fell, revealing the limitations of his method. Although his reasoning was impressive, there was still an element of uncertainty, a flaw that no one could ignore.
Indeed, without measuring the height, Reo's reasoning seemed to collapse. Many looked down, already convinced that all hope was lost.
Then a man in his forties calmly approached the group. His composed demeanor contrasted with the general panic.
"Perhaps I can help you..." he said in a deep voice. "I used to be an architect."
Everyone turned to him, a glimmer of hope rekindled. Reo, intrigued, pointed to the translucent barrier that formed the vaulted ceiling and asked him:
"Can you tell me, on average, how tall a three-story building is here in Japan?"
The man looked around carefully before replying confidently:
"What you see there is a sankaidate. Generally, it varies between 9 and 12 meters. But here, I don't see any signs of reinforced concrete... so I'd say we're closer to 9 meters than 12."
"So you're going to base your calculations on an approximate measurement?" asked the architect, frowning.
Reo nodded confidently.
"The translucent barrier is exactly the same height as a three-story building. That's enough for my calculations."
He quickly took his measurements, scribbling invisible numbers in the air, his gaze shifting from the length indicated on the sign to the width he had estimated with his steps. After a few moments of silence, his eyes lit up.
"There's a clear difference..." he announced. "Tunnel number 2, Toyosu, is exactly 13,500 cubic meters."
Whispers spread through the crowd, everyone holding their breath as he continued:
"In this tunnel, the volume corresponds perfectly to the mask's capacity: 13,500 O₂. So this is the right passage."
A heavy silence fell, immediately followed by exclamations halfway between relief and disbelief.
Everyone finally relaxed, letting out sighs of relief. The faces contorted with fear gradually relaxed, and a collective sense of security set in: thanks to Reo, survival finally seemed possible. Quickly, applause broke out, voices cheering the young boy as a hero, a savior despite his age.
Reo, aware that his role was not over, approached the group of four who had called out to him earlier. He addressed the leader directly, calmly and confidently:
"The tunnel to choose is the second one, Toyosu."
The leader, surprised by Reo's sudden arrival, froze for a moment. He blinked, then, regaining his composure, held out his hand and asked:
"Thank you... and what's your name?"
Reo replied simply:
"You can call me Reo."
But the leader, unperturbed, wanted more details. He introduced himself in turn:
"My name is Koki Chiyama. "
Then, pointing to the other three members of his group, he said: "This is Ken, this is Bozu, and this one... you can call him Baka."
Finally, he turned back to Reo: "And you... what's your full name?"
Reo hesitated for a moment, then replied:
"Reo Kanzaki." "
Koki repeated his name aloud, looking thoughtful. A smile appeared on his lips, and in a surprising gesture, he patted Reo vigorously on the back, laughing:
"Reo Kanzaki... I'll get you back for that!"
Then, still laughing, Koki rejoined his group, leaving Reo standing motionless. The young boy remained frozen, his eyes wide open, unable to blink or look away. Every fiber of his body seemed paralyzed, as if his senses had been overwhelmed by the abruptness and intensity of the interaction. He didn't move, completely shaken, unable to regain his composure after what he had just heard.