Leon spent three days at the Aurora Bureau's temporary base.
During those three days, he immersed himself almost entirely in the cramped laboratory next to Howard's. The room was small, about fifteen square meters, furnished with a metal workbench, a chair, a filing cabinet, and a few cardboard boxes in the corner. Inside the boxes were various instruments Howard had scavenged from storage—a spectrum analyzer, an oscilloscope, a signal generator, and some military‑grade equipment Leon couldn't even name.
He took all of them apart, reassembled them, and recalibrated them in his own way. Howard came to watch once, stood in the doorway for ten minutes, and then left without a word. He didn't ask what Leon was doing, because he couldn't understand it. The mathematical formulas, the physical models, the equations derived from analogies between mana and electromagnetic waves—all of it lay beyond his expertise.
On the third afternoon, Leon spread a map across the workbench.
The map, provided by the Aurora Bureau, marked the terrain, buildings, roads, and known monster distributions in the Boston area and its surroundings. He circled several locations with a red pen, then used a blue pen to connect them, sketching out possible routes.
"Made your decision?" Zoe leaned against the doorway, a cup of coffee in her hand.
"Yes." Leon tapped the red‑circled spot on the map with his pen tip. "MIT's old campus."
Zoe walked over and looked down at the map. "Reasoning."
"Infrastructure," Leon said. "MIT has its own independent power system, including a small nuclear reactor and several emergency generators. As long as fuel and coolant last, it can theoretically provide power for years."
He pointed to several buildings marked on the map.
"Research equipment. The physics, chemistry, and biology labs are all in this area. There's a good chance the equipment is still intact. I need that equipment to precisely measure mana's physical parameters."
His pen moved to a blue‑circled zone.
"Location. The MIT campus sits on the south bank of the Charles River, surrounded on three sides by water, with only a land route to the north. If we set up defenses at a few key points, it can become a naturally fortified position."
Zoe looked at the map, silent for a few seconds. "Have you been to MIT?"
"I studied there for five years and taught for two," Leon said. "Every building, every road, every underground tunnel—I could walk them with my eyes closed."
Zoe nodded, asking nothing more. "How many people will you need?"
"A single squad should be enough. More people would only draw the monsters' attention." Leon thought for a moment. "Six to eight people, preferably with combat experience, who know how to move through ruins."
"I'll lead the squad." Zoe set her coffee on the table. "I'll bring six more, all veterans of the advanced team. We leave tomorrow morning."
"Tomorrow morning is too late." Leon shook his head. "It's three in the afternoon now. If we leave immediately, we can get there before dark. Spending the night in the ruins is far more dangerous than moving during the day."
Zoe looked at him. "Are you sure?"
"I'm sure."
Zoe asked no more. She turned and left the lab to assemble her team.
At four in the afternoon, the team was assembled.
Counting Leon, there were eight of them. Zoe was the captain and tactical commander. Marcus Lee served as the main attacker—the same burly man who had sparred with Leon on the training ground. The other five were: Alina Volkova, a tall, blonde, blue‑eyed sniper who spoke with a slight Russian accent; Carlos Rodriguez, the communications specialist, carrying a modified military radio on his back; Sakurai Haruki, a taciturn Japanese‑American young man specializing in close combat, a pair of tactical short swords hanging at his waist; and two young soldiers whose names Leon didn't catch, responsible for logistics and support.
They drove two modified Humvees, leaving the base by the north gate and heading toward the MIT campus along a pre‑planned route.
The Humvees' windows had been replaced with steel plates, leaving only firing ports. Extra antennas and sensors were mounted on the roofs to detect mana fluctuations. The bodies were painted matte black, nearly invisible in the twilight.
Leon sat in the passenger seat of the second vehicle, map in hand, occasionally looking up to observe the surroundings. Zoe sat behind him, checking her compound bow.
"When did you start using a bow?" Leon asked.
"I learned it in the military." Zoe drew the string, checking the tension. "Later I found that arrows are more effective against monsters than bullets. A bullet to a vital spot isn't always fatal, but an arrow infused with mana has greater penetration than an armor‑piercing round."
"What's your ability?" Leon asked.
Zoe glanced at him. "Enhanced dynamic vision. I can see the trajectory of fast‑moving objects and predict where they'll be a second later."
"So you could put an arrow through a Steel‑Mane Wolf's eye as it charged."
"That's why I can do it." Zoe put the bow away. "What about your fire magic? You learned it in only three days?"
"Not learned—derived," Leon said. "Spell structures are the physical realization of mathematical formulas. Once you understand the formulas, the rest is calculation."
Zoe was quiet for a moment. "The way you talk reminds me of someone."
"Who?"
"My sister." Zoe's voice was flat, but Leon noticed her hand tighten on the bow case. "She was the kind of person who wanted to explain everything with formulas."
"Where is she now?"
Zoe didn't answer.
The vehicle fell silent, filled only by the engine's roar and the crunch of gravel under the tires. Leon didn't press; he had already read the answer in Zoe's tone.
The convoy headed southeast along the planned route. On both sides of the road stretched endless ruins—collapsed buildings, overturned vehicles, the occasional corpse. Some corpses were human, some were mutated creatures, and some had rotted beyond recognition.
Leon kept his mana sense active, monitoring the energy fluctuations around them. The background energy intensity was higher than the day before. The frequency hadn't changed, but the amplitude had increased by about eight percent.
"The energy concentration is still rising," he murmured. "Not a steady release—an accelerating one."
Zoe heard him. "What does that mean?"
"It means the monsters will grow stronger and mutate faster. The Shadow Cats and Steel‑Mane Wolves we're facing now might be the weakest ones."
The vehicle fell silent again.
The Humvees stopped at an intersection. Ahead, the road was blocked by a wall of wrecked cars, impassable. Zoe got out, scanned the surroundings with binoculars, then returned to the vehicle.
"Detour. Take Memorial Drive along the Charles River."
The convoy turned and headed toward the river along a relatively intact road. About ten minutes later, the Charles River came into view.
The river was wider than Leon remembered; the water level had risen, flooding parts of the bank. The water was an abnormal dark green, with white foam floating on the surface. On the opposite bank lay downtown Boston, its skyline completely transformed—high‑rises toppled, smoke and dust everywhere, that eerie gray‑white light swirling above the city like an aurora, yet not quite an aurora.
"Too quiet." Marcus's voice came over the radio from the first vehicle. "We've been driving this long and haven't seen a single monster."
Leon felt the same. From the moment they left the base until now, about twenty minutes of driving, his mana sense had detected no obvious energy sources. That was highly abnormal. At this energy concentration, monsters should be everywhere, not absent.
"It could be a trap," he said. "They're learning."
"What's learning?" Zoe frowned.
"The monsters," Leon said. "If they have basic intelligence, they'll learn to avoid human patrol routes and gather in more concealed places. This route may already be familiar to them, which is why they're not active in this area."
"Then where are they active?"
"Where we don't want them to be."
The convoy continued. After another ten minutes, the MIT campus appeared in view.
The iconic Great Dome was still intact, but several surrounding buildings had collapsed. The campus trees were all dead, bare branches pointing to the sky like countless withered hands. The ground was covered with a layer of gray‑white dust, its composition unknown.
Leon had the convoy stop at the campus perimeter and got out to observe.
His mana sense finally detected energy sources—deep inside the campus, at least a dozen light points, each with brightness comparable to a Shadow Cat. They were scattered, not clustered, as if each was claiming its own territory.
"Twelve to fifteen Shadow Cats," he said. "Scattered across the campus, no concentration."
Zoe also got out and raised her binoculars. "Can we go around them?"
"No." Leon shook his head. "Their positions cover the main routes to the main lab building. No matter which direction we approach from, we'll run into at least two or three."
"Then we clear them out." Marcus jumped out of the first vehicle, rolling his shoulders. "Just a few cats."
"Not a few," Leon said. "It's over a dozen. And we don't know if there's a stronger individual hiding in the shadows. Rushing in would be suicide."
Marcus curled his lip but didn't argue.
Leon crouched down and sketched a rough map of the MIT campus in the dust with his finger. He marked every building, every pathway, and every energy source he had detected.
"We need a plan," he said. "Not picking them off one by one, but taking them all out at once."
Zoe crouched beside him, looking at the sketch. "Do you have a plan?"
"Yes." Leon used a twig to draw lines on the sketch. "North of the campus is the Charles River, south is a residential area, east is the main campus, west is a parking lot. The Shadow Cats are concentrated in the east and south; only a few are scattered in the north and west."
He pointed to a spot on the sketch.
"Here, the underground parking garage. Enclosed space, only one entrance and one exit. If we can lure the Shadow Cats in and set explosives at the exit, we can wipe out most of them in one go."
"How do we lure them?" Zoe asked.
Leon stood and looked at Carlos. "Can your radio emit high‑frequency sound waves?"
Carlos blinked. "Theoretically, yes. The radio's frequency range is 1 to 30 megahertz. Sound waves are 20 to 20,000 hertz—different bands."
"Modify it," Leon said. "Connect the signal generator's output to a speaker, bypass the RF amplifier, and drive the voice coil directly. Tune the frequency above 20,000 hertz—inaudible to humans, but cats can hear it. Even mutated, a Shadow Cat's auditory system should still be similar to a feline's. High‑frequency sound will irritate their auditory nerves, causing discomfort or even pain, forcing them to leave their hiding places."
Carlos opened his mouth as if to say something, but in the end just nodded and began tinkering with the radio.
Zoe looked at Leon, something unreadable in her eyes. "You said you studied at MIT for five years?"
"Five years for undergrad and PhD, plus two years of postdoc."
"Not military academy?"
"No."
"Then where did you learn tactical analysis, environmental assessment, psychological prediction?"
Leon thought for a moment. "Probably chess. I played a lot of chess when I was young. The essence of tactical analysis is predicting the opponent's next move. Whether on a chessboard or a battlefield, the logic is the same."
Zoe was silent for a few seconds, then stood and issued orders to the team: "Everyone, follow Winchester's plan. Marcus, take two men to set up explosives in the parking garage. Alina, find a vantage point for sniping any that slip through. Sakurai, you and I will drive the Shadow Cats into the garage. Carlos, you're on the sonic device."
She turned to Leon. "What about you?"
"I'll handle the calculations," Leon said. "The timing of the detonation, the positions of the Shadow Cats, the force of the blast—all need precise calculation. A one‑second difference, and the effect will be greatly reduced."
Zoe nodded. "Move out."
At 6:17 PM, the sky began to darken.
Marcus placed six explosive charges at the parking garage's exit, using a plastic explosive called C‑4, about two kilograms in total. He marked each charge point and connected them to a remote detonator.
Alina climbed to the roof of a still‑standing classroom building south of the campus and set up her sniper rifle. Her position overlooked the entire parking garage area, with a clear field of fire.
Carlos modified the radio and fixed an external speaker at the garage entrance. He adjusted the frequency, and the speaker emitted a sharp, almost inaudible hiss.
"Set the frequency to 25,000 hertz," Leon said. "Test it at low power first."
Carlos turned down the power and activated the sonic device.
In the distance, Leon's mana sense caught the change. Those energy sources in the east and south began to move—not toward a single direction, but away from the sound source. Several Shadow Cats started moving west, heading straight for the underground garage.
"It's working," Leon said. "Increase the power, full output."
The sonic device was cranked to maximum power. The 25,000‑hertz waves propagated through the air; though inaudible to human ears, they produced a subtle pressure, like something squeezing the eardrums.
In his mana sense, over a dozen energy sources all began to move. Like a flock of sheep driven by instinct, they fled from the sonic stimulus toward the direction without sound. And that direction had only one exit—the underground parking garage.
The first Shadow Cat dashed into the garage.
The second, third, fourth…
Leon crouched in a building across from the garage entrance, tracking each Shadow Cat's position with his mana sense. They darted around inside the garage—some searching for an exit, some attacking each other, some trying to climb the walls.
"Twelve," he murmured. "All inside."
Zoe crouched beside him, holding the remote detonator. "When do we blow it?"
"Wait," Leon said. "They're still adjusting to the sound. If we detonate now, some might escape. Wait until they're fully acclimated, their neural responses slowed, then blow it."
They waited another two minutes.
In his mana sense, the Shadow Cats' energy sources grew stable. They stopped darting around and gathered at the deepest part of the garage, farthest from the sound source. They had found a relatively quiet area and began to curl up, as if waiting for the sound to stop.
"Now," Leon said.
Zoe pressed the detonator.
A muffled explosion came from underground, the ground shaking violently. A cloud of dust and debris shot from the garage entrance, smoke filling the area. The blast wave surged out from below, carrying a wave of searing heat.
In Leon's mana sense, twelve energy sources vanished simultaneously.
No, not all. One remained—its brightness far higher than a Shadow Cat's, its pulse frequency faster. It had moved the instant of the explosion, so fast that Leon's perception could barely track its trajectory.
It burst out of the garage.
A black shadow shot from the smoke, so fast it left an afterimage in the air. It was twice the size of a Shadow Cat, its fur not black but deep red, like dried blood. Its eyes were not green but gold, the pupils vertical slits burning with a cold flame.
"Red‑Mane Cat," Zoe said, her voice low. "Mid‑grade magical beast. Rarer than a Steel‑Mane Wolf, but more dangerous."
The Red‑Mane Cat didn't flee after leaving the garage. Instead, it turned toward Leon and Zoe. Its body lowered slightly, golden eyes locked on them, tail slowly swaying behind it.
It was assessing. Calculating. Searching for the best angle of attack.
Leon could feel it—this creature had intelligence. Not just instinct, but the ability to think, judge, and formulate tactics.
"Alina, can you get a shot?" Zoe pressed her earpiece.
"Bad angle. It's moving." Alina's voice came through the earpiece. "I need it to stop for one second."
One second. Leon looked at the Red‑Mane Cat, at the energy trajectories around its body, at the interference patterns of its waveforms. Its energy flow was far more complex than a Shadow Cat's; the waveform wasn't a single frequency but multiple layers superimposed, forming a complex resonant structure.
Its weak point wasn't in its joints, not in its neck, but—
"Its abdomen," Leon said. "Its energy core is in the abdomen, not the chest. The fur there is less metallized than the rest, but there's a patch about the size of a palm that isn't covered at all."
Zoe didn't ask how he knew. She raised her compound bow, nocked an arrow, and drew the string to full draw.
The Red‑Mane Cat moved.
Its speed was at least twice that of a Shadow Cat, so fast that Leon's mana sense could only catch a blurred trail. It didn't charge in a straight line—it zigzagged in the air, tracing a Z‑shaped attack path.
Zoe's eyes darted rapidly, her pupils shrinking to pinpoints. Her enhanced dynamic vision worked at full capacity, tracking the Red‑Mane Cat's trajectory.
She released the string.
The moment the arrow left the bow, Leon saw it—a faint layer of mana clung to the arrow's tail, forming a thin energy trail in the air. The arrow was far faster than a normal shot, not because of the bow's power, but because the mana was accelerating it.
The arrow struck the Red‑Mane Cat's abdomen.
Not the vital spot—at the last instant, the cat twisted, and the arrow only grazed its flank. Black fluid sprayed from the wound, and the Red‑Mane Cat let out a piercing shriek, flipping in mid‑air before landing.
It didn't run.
It turned, golden eyes fixed on Zoe, mouth open to reveal two rows of sharp teeth. Its flank bled, but the wound was healing rapidly—in Leon's mana sense, its energy core was pulsing at high speed, channeling energy to the injury to accelerate tissue regeneration.
"Its regeneration rate is ten times faster than a Shadow Cat's," Leon said. "If we don't kill it in one strike, it will just keep healing."
Zoe nocked another arrow.
The Red‑Mane Cat didn't give her another chance. Its body launched upward, not in a zigzag this time, but in a straight line—at maximum speed, directly at Zoe.
Zoe didn't dodge. Her eyes locked on the cat's trajectory, drawing the string to full draw again.
The arrow flew.
It struck the Red‑Mane Cat's head—but at the moment of impact, the cat turned its head, and the arrow only grazed its ear, failing to deliver a fatal blow.
Its claws were already swinging toward Zoe's face.
Sakurai Haruki rushed in from the side.
His speed was nearly as fast as the Red‑Mane Cat's. Body low, twin blades drawn, one swinging at the cat's foreleg, the other stabbing toward its abdomen. Both strikes landed almost simultaneously—the foreleg joint was sliced open, and the abdominal blade pierced near the core.
The Red‑Mane Cat's body recoiled violently. Sakurai was thrown off, slamming into a wall with a grunt.
But the cat's speed had dropped dramatically. Blood poured from its abdominal wound; its core was damaged, its energy supply faltering. Its movements slowed, and the golden light in its eyes began to dim.
Alina's rifle cracked.
The bullet struck the Red‑Mane Cat's abdomen—the palm‑sized patch of unprotected skin. It pierced the skin and hit the energy core.
The Red‑Mane Cat's body stiffened.
The golden light in its eyes went out. Its body began to shrivel, the red of its fur fading to gray‑white. It collapsed to the ground, motionless.
Leon walked over, crouched, and looked at the corpse. There was a fist‑sized hole in its abdomen, revealing a shattered energy core whose fragments still glowed faintly.
"Analyze," he thought.
[Mana core detected (Red‑Mane Cat, mid‑grade). Absorb? Absorption yields 120 KE.]
"Absorb."
The light points turned into a stream of light that vanished into his chest. New information flooded his consciousness—the Red‑Mane Cat's energy flow patterns, weak point distribution, behavioral patterns. Far more complex than the Shadow Cat's data, but also far more complete.
[KE balance: 130.]
Leon stood and looked around. Smoke still rose from the parking garage entrance; the twelve Shadow Cats lay buried beneath the rubble. The Red‑Mane Cat's corpse lay at his feet, already gray‑white.
The campus was cleared.
"Stronghold selection complete," he said to Zoe. "Next, we establish the defenses."
Zoe put away her bow and looked at this young scientist. His clothes were covered in dust and black fluid, the wound on his left hand still seeping blood, but his gaze remained calm, as if he had just completed an ordinary experiment in the lab.
"You really never fought in a war before?" she asked.
"No," Leon said. "But I've played a lot of chess."
He turned and walked toward the main laboratory building of the MIT campus. The five‑story concrete structure was still standing; cracks marred its exterior, but there was no structural damage. The antenna on the roof was still there, most of the windows were intact, and the door was locked—a good sign, meaning nothing had gotten in.
He smashed the lock with his axe and pushed the door open.
Inside was pitch black, the air thick with dust and the smell of chemicals. He used his phone for light, sweeping the lobby—familiar white walls, gray floors, metal tables and chairs. Everything looked as it did in his memory, just covered in a thin layer of dust.
His lab was on the fourth floor.
Leon climbed the stairs, each step making them creak. His mana sense told him there were no energy sources in the entire building. Clean.
The fourth‑floor lab door was also locked. He smashed the lock and pushed it open.
A standard quantum physics lab. Optical table, lasers, vacuum chamber, detectors, oscilloscopes, computers. All the equipment was still there, just without power.
But power could be restored.
Leon walked to the window, pushed it open, and looked out at the campus. In the twilight, the dead trees and collapsed buildings cast long shadows. The Charles River flowed in the distance, its surface reflecting that eerie gray‑white light.
"Phase One, safe zone," he murmured.
Deep in his consciousness, the pages of the Book of Truth turned.
[System Task Updated: Establish Safe Zone (1/3).]
Leon stood at the window, looking at the campus that had once been his second home. Now, it would become his first stronghold in the apocalypse.
He would build a lab here and continue researching the nature of magic. He would set up defenses here, protecting himself and those he chose to protect. He would set out from here to explore this altered world and find answers to all his questions.
"Let's get to work," he said.
Behind him, Zoe leaned against the doorframe, watching his silhouette. The light of the setting sun streamed through the window, gilding his outline.
She thought of someone. Someone who wanted to explain everything with formulas. Someone who never came back.
Zoe lowered her eyes and turned away.
Some wounds time cannot heal.
But at least she had found someone worth following.