The night at the MIT campus was quieter than Leon had expected.
It wasn't the kind of quiet that brings comfort, but something deeper, more primal—the silence of a forest where every animal senses the presence of an apex predator and collectively holds its breath. The pervasive gray‑white light became even more pronounced at night, seeping down from the sky and coating every building, every tree, every fragment of rubble with a sickly glow.
Leon stood on the roof of the main laboratory building, scanning the surroundings with binoculars. His mana sense remained active, but its ten‑meter radius was too small—almost useless in open terrain. He needed a way to detect threats over a larger area.
"You've been up here for an hour." Zoe's voice came from the stairwell. She climbed onto the roof, carrying two steaming cups of coffee—real coffee, not instant, sourced from somewhere unknown. "Come down and eat something. Marcus found some canned goods and a pack of survival biscuits that haven't expired."
Leon took a cup and sipped. The bitter liquid slid down his throat, bringing warmth to his stomach. "I need more time. The defense system has to be in place before dark tomorrow. Otherwise, we won't be able to hold such a large area at night."
Zoe stood beside him, also gazing at the distant ruins. "How do you plan to build it?"
Leon lowered his binoculars, pulled out his notebook, and flipped to the page covered with sketches.
"Three defensive layers," he said, tracing the sketches with his finger. "Outer layer: sonic‑based monster deterrent devices. They'll cover a five‑hundred‑meter perimeter around the campus, using ultrasonic waves at specific frequencies to irritate the monsters' auditory nervous systems, forcing them away from the area."
Zoe frowned. "The device you used at the parking garage? It worked well, but it only deterred low‑grade monsters. That Red‑Mane Cat wasn't affected."
"Because the frequency was wrong," Leon said. "The auditory systems of Shadow Cats and Red‑Mane Cats are different; they're sensitive to different ultrasonic bands. I need more data to determine the optimal frequencies. But the outer layer's purpose was never to block mid‑ and high‑grade monsters—it's only meant to reduce harassment from low‑grade creatures and lower our alert burden."
He pointed to the second layer on the sketch.
"Middle layer: a mana‑sensing early‑warning array. It will cover a hundred‑meter radius around the campus core, using a runic formation to amplify the range and precision of mana sense. In theory, it can extend my perception from ten meters to a hundred‑meter radius and distinguish between different levels of energy sources."
Zoe stared at the complex geometric shapes on the sketch. "You know how to draw runes?"
"I'm learning," Leon said. "The Aurora Bureau has only deciphered ten percent of the runes, but the basic ones are enough to build a simple perception‑amplifying array. The rest I'll have to derive myself."
Zoe was silent for a few seconds. "The way you talk really reminds me of someone."
"Your sister."
"Yes." Zoe's voice was soft. "She always said things like 'I'm learning' and 'I'll derive it myself.' As if there was nothing in this world that couldn't be learned or derived."
Leon didn't respond. He knew this wasn't a moment that needed a response.
"What's the third layer?" Zoe changed the subject.
Leon turned to the next page of his notebook. This sketch was even more complex, covered with dense lines, symbols, and mathematical formulas.
"Inner layer: a composite trap system," he said. "It will cover a fifty‑meter radius around the core buildings, including the main laboratory, the generator room, and the supply warehouse. The traps have two components: an electromagnetic pulse generator, built from modified capacitor arrays to create a directional EMP that can paralyze a monster's nervous system, and an ice‑based magic circle that uses low temperatures to freeze the monsters' mobility."
"EMP and ice magic?" Zoe raised an eyebrow. "How do those two work together?"
"They don't combine; they complement each other," Leon said. "The EMP targets the monster's energy core—at its essence, the core is a bio‑electromagnetic field generator, and a strong electromagnetic pulse can interfere with or even temporarily shut it down. The ice magic targets the monster's body—low temperatures slow their reaction speed and reduce muscle contraction efficiency. Together, even if they can't kill a mid‑grade monster, they can buy enough reaction time."
Zoe looked at him with an unreadable expression. "How long did it take you to design this?"
"Since I decided on this location." Leon closed the notebook. "About four hours."
"Four hours."
"Most of it was calculating the structural parameters of the runes. The geometry of a magic circle determines the efficiency of energy flow. An angle off by one degree can reduce efficiency by thirty percent."
Zoe took a sip of her coffee and asked no more.
At six in the morning, Leon began constructing the defense system.
The outer layer was the simplest, requiring few materials and no precise calculations. He set up a sonic emitter at each of the four cardinal directions around the campus—modified military radios from Carlos as the signal sources, and high‑frequency speakers scavenged from the physics lab as the output devices.
The speakers were mounted on temporary iron stands about three meters above the ground, facing outward from the campus. Each emitter was connected to an independent small generator—gasoline generators found in the campus maintenance shed, capable of running for twelve hours on a full tank.
"What frequency?" Carlos crouched beside the first emitter, a frequency meter in his hand.
"Start at 20,000 hertz, adjust every two hours," Leon said. "I need to test the deterrent effect of different frequencies on different monsters. Record any changes in monster activity after each adjustment."
Carlos nodded and began setting parameters on the frequency meter.
Leon walked to the campus center to set up the middle layer—the mana‑sensing early‑warning array.
This was the most complex of the three layers, requiring precise geometric calculations and a deep understanding of runic structures. Leon crouched in the plaza before the main laboratory building, using chalk to draw a twenty‑meter‑diameter circle on the ground.
At the center of the circle was a six‑pointed star, each point a node. The nodes were connected by curved lines, forming a complex, symmetrical pattern. The position of each node corresponded to a specific mathematical constant—pi, Euler's number, the golden ratio… Leon spent two hours calculating these constants to six decimal places and converting them into geometric distances.
"What are you drawing?" Marcus stood nearby, holding a roll of wire, eyeing the pattern on the ground with curiosity.
"A magic circle," Leon said without looking up. "Or an energy‑focusing array. Call it what you like."
Marcus scratched his head. "I thought magic circles were those cool, glowing things drawn on parchment."
"Those are from movies," Leon said. "A real magic circle is mathematics. These curves aren't random; they're the projection trajectories of energy on a plane. Every arc, every intersection has a corresponding mathematical expression."
He pulled a handful of iron nails from his pocket—not ordinary nails, but the batch he'd found in the grocery store, infused with his mana until faint luminous patterns appeared on their surfaces. He hammered them into the ground at the chalked node positions, leaving only about a centimeter of the nail head exposed.
Six nails, six nodes.
Leon stepped to the center of the circle, closed his eyes, and sank his consciousness into the Book of Truth.
[Runic formation detected. Type: Perception Amplification. Integrity: 100%. Activate with system assistance?]
"Yes."
The pages of the Book of Truth turned, and golden text flowed from his consciousness along an invisible channel toward the magic circle on the ground. The six iron nails lit up simultaneously—not with a harsh glare, but with a soft, golden‑white light, like morning sunlight through thin mist.
The light spread along the chalk lines, filling every curve, every arc. Within seconds, the entire magic circle became a glowing geometric pattern suspended about ten centimeters above the ground.
Leon's mana sense was instantly amplified.
His perception radius exploded from ten meters to fifty, then to eighty, finally stabilizing around a hundred and twenty meters. It wasn't just an expansion of range—the precision improved as well. He could feel every tiny energy fluctuation in the air, distinguish subtle differences between energy sources, and "see" the energy distribution along every hair on the bodies of monsters hundreds of meters away.
The situation around the campus became crystal clear in his perception.
North, across the Charles River, three Shadow Cats wandered. Their energy brightness was moderate, their pulse frequency stable, showing no aggression.
East, among the ruins of the main campus, five Shadow Cats and one larger creature—possibly another Red‑Mane Cat or a different species. That energy source was less bright than the Red‑Mane Cat, but its pulse was faster, suggesting a speed‑type monster.
South, toward the residential area, the densest concentration—at least twenty light points of varying brightness. The brightest was near the level of a Steel‑Mane Wolf, its pulse very slow, as if in hibernation.
West, toward the parking lot, only a few scattered energy sources, all very dim.
"Radius of a hundred and twenty meters." Leon opened his eyes, a hint of excitement in his voice. "Precision is sufficient to distinguish energy sources of different levels. This array can serve as the core of the early‑warning system."
He took out his notebook and recorded the array's parameters: diameter, number of nodes, energy consumption,
The inner layer was the most complex and the one Leon felt least certain about.
The electromagnetic pulse generator required a large number of capacitors and a precise timing‑control circuit. He found enough materials in the physics lab—several large electrolytic capacitors, a high‑voltage power supply, a programmable pulse generator. Assembling them into a device capable of delivering a directional EMP took a full four hours.
The ice‑based magic circle was another challenge. His water magic was still rudimentary, and ice magic—a variation of water magic—required even finer energy control. He tested it dozens of times in the lab before successfully creating his first piece of ice: the size of a fingernail, temperature about minus five degrees Celsius.
"Not enough," he told himself. "I need greater output, lower temperature."
He began re‑deriving the mathematical expression for ice magic. The characteristic frequency of water magic was a mid‑frequency, smooth waveform. Ice magic should be a high‑frequency variant of water magic—higher frequency, steeper waveform, energy release shifting from fluid dynamics to crystallization dynamics.
After deriving the new formula, he tested it five times in the Training Space. Each attempt failed. On the sixth try, the spell structure activated successfully, and a fist‑sized block of ice appeared in his palm, temperature minus fifteen degrees.
"Acceptable," he noted mentally. "Output power is twenty times that of the initial version."
He engraved the ice spell structure onto three copper plates—using mana to etch the geometric pattern onto their surfaces, then infusing the patterns with stored energy. These three copper plates would serve as the core of the ice‑based magic circle; when activated, they would create a low‑temperature zone over a predetermined area.
The composite trap installation took the entire afternoon.
Leon mounted the EMP generator at the entrance of the main laboratory building, facing outward, covering a hundred‑and‑twenty‑degree arc. He buried the ice‑magic copper plates underground around the building, about twenty centimeters deep, plates facing upward. Once activated, they could lower the ground temperature to minus twenty degrees within thirty seconds.
The two systems operated independently but could be linked. The EMP would activate first, paralyzing a monster's nervous system; half a second later, the ice magic circle would activate, freezing its mobility. If a monster could still move after both attacks, it would have to be dealt with by human force.
"Could this stop a Red‑Mane Cat?" Marcus asked, eyeing the buried copper plates with skepticism.
"In theory, yes," Leon said. "The EMP will interfere with its energy core, and the ice magic will reduce its muscle efficiency. Its speed and strength should drop by at least fifty percent. You can handle the remaining half."
"In theory."
"Science only has theory. Practice is the means of validating theory."
Marcus shook his head. "You sound just like my college physics professor."
"That means your college physics professor was a smart man."
By five in the afternoon, all the defensive systems were installed.
Leon stood on the roof of the main laboratory building, using his mana sense to check the status of each system. The outer sonic emitters were working properly, outputting ultrasound in all four directions at 20,000 hertz. In his perception, low‑grade monsters within five hundred meters had noticeably decreased—not completely absent, but about sixty percent fewer than in the morning.
The middle‑layer mana‑sensing array was running stably; all six nodes had consistent energy output with no attenuation. His perception range remained at a hundred and twenty meters, with enough precision to distinguish between different levels of energy sources.
The inner‑layer composite trap system was on standby. The EMP generator's capacitors were fully charged, and the ice‑magic copper plates were pre‑energized. Both systems could be activated within 0.3 seconds.
"Safe zone," Leon murmured.
Deep in his consciousness, the pages of the Book of Truth turned.
[Safe Zone Establishment Progress: 1/3.]
[Stronghold Defense System Assessment: Outer layer — effective, but frequencies require continuous optimization; Middle layer — stable, detection range 120 meters, precision A‑grade; Inner layer — pending validation, needs live testing.]
[Overall Rating: C+.] [Suggestions: Add redundant systems, optimize power supply, expand detection range.]
Leon looked at the assessment and the corner of his mouth lifted. C+. For a temporary stronghold built in a single day, that wasn't bad. And the system had given clear directions for improvement—redundancy, power, perception. All problems that could be solved with technology.
As he was about to go downstairs, the Book of Truth's pages turned once more.
This time, it wasn't a system notification, but a new‑function unlock alert.
[New Function Unlocked: Knowledge Repository.]
[Description: Can record, categorize, and retrieve all analyzed magical information. Including but not limited to: spell structures, rune meanings, monster data, material properties.]
[Current Storage Capacity: Unlimited.]
[Entries Stored: 23.]
A vast virtual space appeared in Leon's consciousness. Not the empty white void of the Training Space, but a structured, organized "library." Rows of virtual bookshelves stood neatly arranged, each labeled—Spells, Runes, Monsters, Materials, Theories…
He "walked" into the library and opened one of the shelves.
[Spell·Fire·Basic] — stored the mathematical expression for fire magic, activation method, energy consumption, proficiency level.
[Spell·Wind·Basic] — stored the complete data for wind magic.
[Monster·Shadow Cat·Low‑Grade] — stored the Shadow Cat's energy structure, weak‑point distribution, behavioral patterns, absorption record.
[Rune·Perception Amplification·Basic] — stored the complete parameters of the runic array he'd used today.
Every entry had detailed descriptions, diagrams, mathematical formulas, and even simulation records from the Training Space.
Leon stood in this virtual library, looking around.
This was his own knowledge repository. He could retrieve any piece of information at any time, deduce new possibilities based on existing knowledge, and cross‑integrate knowledge from different fields.
It was a scientist's ultimate tool.
"System," he thought. "Can the Knowledge Repository be shared with others?"
[Currently cannot be shared. The host can manually export data through output devices (paper, screens, etc.).]
"Can it be upgraded later?"
[Upgradable. Unlock conditions: complete specific tasks or consume KE.]
He noted that information.
As night fell, Leon sat in an office on the fourth floor of the main laboratory building, facing a whiteboard he'd taken off the wall. The board was covered with formulas, diagrams, and arrows, stretching from the top left to the bottom right, like a complex map.
Zoe pushed the door open, carrying two bowls of steaming instant noodles. "Dinner. Marcus made it, with Spam and eggs. He says it's the most luxurious instant noodles he's ever had."
Leon took a bowl, picked up a few strands with a fork, and chewed mechanically. His eyes remained fixed on the whiteboard.
Zoe followed his gaze. "What is this?"
"A theoretical framework." Leon set down his fork, stood, and walked to the whiteboard. "I'm trying to explain magic using scientific theory."
He pointed to the first line at the top left.
"Hypothesis: Mana is the projection of energy from higher‑dimensional space."
He pointed to the derivations below.
"If higher‑dimensional space exists—say, the 11‑dimensional spacetime of string theory—then energy fluctuations in that higher‑dimensional space would produce projection effects in three‑dimensional space. That projection is what we observe as mana."
Zoe frowned. "Higher dimensions? String theory? Can you say that in plain language?"
Leon thought for a moment, then rephrased.
"Imagine a three‑dimensional sphere passing through a two‑dimensional plane. What would a two‑dimensional creature see?"
Zoe considered. "A circle. First a small dot, then bigger, then smaller, then gone."
"Exactly," Leon said. "The circle that the two‑dimensional creature sees is the projection of the three‑dimensional sphere onto the plane. The circle itself isn't the sphere, but it contains information about the sphere—its size, position, direction of motion."
He pointed to the formulas on the board.
"Mana is the projection of higher‑dimensional energy into three‑dimensional space. The mana fluctuations, energy cores, and spell effects we observe are all three‑dimensional projections of higher‑dimensional phenomena. Magic doesn't violate the laws of physics—it's physics we didn't know about before, now coming into play."
Zoe was silent for a long time.
"So you're saying magic is really higher‑dimensional physics?"
"You could put it that way," Leon said. "If we can build a complete theory of higher‑dimensional projection, we could precisely predict the behavior of mana, the direction of monster evolution, and perhaps even find a way to reverse this disaster."
Zoe looked at him, at the dense formulas on the whiteboard, at this young man still trying to explain everything with science in the midst of the apocalypse.
"Do you believe you can do it?" she asked.
"I believe in mathematics," Leon said. "Mathematics doesn't lie."
He walked back to his desk, sat down, and continued eating the noodles, now slightly cold.
Outside the window, the gray‑white light flowed slowly across the night sky, like an invisible river. In the distance, a monster howled, the sound waves spreading through the air, creating complex interference patterns.
Leon ate his noodles while constructing the mathematical framework of higher‑dimensional projection theory in his mind. The framework was still rough, with many parts based on hypotheses that needed experimental validation. But he knew the direction was right.
Mathematics doesn't lie.
Late at night, Leon stood alone on the roof of the main laboratory building.
All three defensive layers were active, appearing in his mana sense as three different colors—the outer sonic waves were blue ripples, the middle magic circle a golden glow, the inner composite traps red pulses. The three colors intertwined, forming a three‑dimensional, dynamic defense network.
He looked down at the campus bathed in that glow.
This was his first stronghold in the apocalypse. Not a refuge, not a hiding place, but a true foothold—a place to stand, to grow, to strike back.
He would build a lab here and study magic with scientific methods.
He would train a team here, using a rational mind to confront a chaotic world.
He would set out from here to find answers to the questions that still had none.
The pages of the Book of Truth turned in the depths of his consciousness, golden text appearing:
[Phase One: Establish Safe Zone — Progress (1/3).]
[Next Goals: Expand detection range, optimize power supply, establish stable supply routes.]
Leon closed the book in his mind and turned to leave the roof.
There was still much work to do tomorrow.
But tonight, this stronghold belonged to him.
To Winchester.