At 3 PM the next day, the sounds of club activities echoed throughout the campus.
Okabara Kyogumichi, carrying a hiking backpack full of gear, stood at the back door of the west wing of the old school building, watching Chitanda Eru poke her head out of the Drama Club activity room window and give him an "OK" signal.
According to the plan, Chitanda Eru was responsible for keeping watch in the prop warehouse and reporting any movements via Bluetooth earphones in real-time, while Kyogumichi would enter the basement to explore.
Last night, the two had confirmed that the Drama Club members were attending an exchange meeting outside school this afternoon, so the entire west wing would be empty.
Kyogumichi put on his headlamp and pushed open the side door of the prop warehouse.
The warehouse was filled with the smell of sawdust and paste, and sunlight streamed in diagonally through the transom window, casting beams of light on the floor where countless dust particles danced.
Chitanda Eru was squatting by a pile of miscellaneous items, tapping the wall with her fingers—that was precisely the location of the false wall.
"It sounds hollow when I tap it," she whispered, her fingertip tracing a slightly darker wooden board, "There are gaps at the edges, so it should be pry-able."
Kyogumichi took out an entrenching tool from his backpack, inserted it into the gap between the wooden board and the wall, and pried it open with force.
With a soft "click," the wooden board cracked.
He followed the gap and dismantled the entire false wall, revealing the pitch-black entrance to a passage, from which a damp, musty smell wafted out.
"I'm going in," Kyogumichi said, turning on his waterproof flashlight, its beam piercing the darkness.
"Be careful, the passage is only half a meter wide, and there might be collapses," Chitanda Eru's voice came through the earphones, tinged with worry, "I'll check in with you every five minutes."
Kyogumichi bent down and squeezed into the passage, the flashlight beam swaying ahead.
The brick walls on both sides of the passage were covered in moss, and water droplets occasionally fell from above, hitting his helmet with a "thump-thump" sound.
He walked very slowly, only moving forward after ensuring each step was firm—the Basic Perception (lv.1) and Danger Perception (lv.1) exchanged from the system allowed him to vaguely detect whether there were hollows under his feet, which was especially useful in the narrow passage.
After walking about ten meters, a rusty iron door appeared ahead.
A brass lock hung on the doorknob, its core long since clogged with rust.
Kyogumichi took out wire cutters from his backpack and squeezed them with force; the clasp snapped instantly.
The moment he pushed open the iron door, a strong smell of rust mixed with fishy water surged out.
The flashlight beam swept across, illuminating a huge underground space—this was the "回"-shaped basement, with knee-deep water in the central area, the surface as calm as a mirror, reflecting the flickering light spots.
Kyogumichi changed into tall rubber boots and stepped into the water.
The icy liquid instantly soaked through his boots; he shivered but continued to move steadily forward.
According to the blueprint, the special storage room should be directly beneath the central area, which is the center of the "回" character.
Some rotting wooden box fragments floated on the water, and occasionally, rats could be seen scurrying from behind the wooden boxes, creating ripples.
Kyogumichi's beam swept over the walls, which were covered with blurred graffiti, mostly "Help me" and "Let me out" written in red paint, the lettering distorted as if written in extreme fear.
"Do you see anything?" Chitanda Eru's voice came through the earphones on time.
"There's strange graffiti on the walls, possibly left by people trapped here back then," Kyogumichi avoided a floating wooden board, "I'm almost at the central area."
Passing through the flooded area, he finally saw the entrance to the storage room.
It was a metal door embedded in the ground, engraved with complex patterns, with a circular groove in the center that looked like some kind of keyhole.
Kyogumichi squatted down and carefully illuminated the groove with his flashlight—there were six small holes inside, arranged in a hexagon.
He suddenly remembered the fox mask in Chitanda Eru's cousin's photo; the mask's forehead also seemed to have a similar hexagonal mark.
"The lock on the storage room door is hexagonal and requires a special key," Kyogumichi said into the microphone, "Do you remember what was on the forehead of the fox mask in that group photo?"
There was a few seconds of silence in the earphones, then Chitanda Eru's excited voice came through: "There were six dots! Arranged in a hexagon! I thought it was just decoration at the time!"
"It seems the key is that mask," Kyogumichi frowned, "But the mask is still on the Drama Club's prop shelf right now."
"I'll go get it!" Chitanda Eru's voice was accompanied by the sound of her running and panting, "Wait for me, I'll be right back."
Kyogumichi hung up the call and sat on a dry wooden box to wait.
The flashlight beam swept back and forth across the storage room door, and he suddenly noticed words hidden within the patterns—it was "Shadow Box" written in ancient Japanese.
He reached out to touch the words, his fingertips feeling the cold metal.
Just then, Chitanda Eru's startled cry suddenly came through the earphones: "Someone's coming! It's Yoshida-sensei!"
Kyogumichi's heart sank: "Hide! Don't get caught!"
"He's entered the prop warehouse… Ah! He saw the false wall!" Chitanda Eru's voice was filled with panic, "He's coming towards the passage!"
Kyogumichi immediately turned off his flashlight, and darkness instantly swallowed the entire basement.
He could hear heavy footsteps coming from the passage, as well as Yoshida-sensei's heavy breathing.
"It was you after all…" Yoshida-sensei's voice sounded at the passage entrance, hoarse with an almost insane quality, "Ten years, and still someone wants to uncover this secret…"
Kyogumichi held his breath, hiding behind the wooden box.
He could feel the other party's footsteps getting closer and closer, the ripples in the puddles spreading to his feet.
"Principal Sato was right, we shouldn't have kept this place…" Yoshida-sensei's voice was tearful, "Those children… it's all my fault for not stopping them…"
Just then, Chitanda Eru's hushed voice came through the earphones: "Okabara-san, I got the mask! Should I throw it to you from the window?"
Kyogumichi's heart stirred, and he whispered into the microphone: "Throw it onto the water in the central area."
He quietly shifted his body, moving closer to the water.
A few seconds later, a black object flew in from the transom window above the passage, falling into the water with a "plop" and splashing water.
It was the fox mask!
Kyogumichi immediately pounced, grabbing the mask before it sank to the bottom.
Almost simultaneously, Yoshida-sensei's flashlight beam swept over, illuminating the mask in his hand.
"That's… Nao's mask!" Yoshida-sensei shrieked, pouncing like a madman, "Give it back to me! Put it back in the storage room!"
Kyogumichi dodged sideways, simultaneously placing the mask onto the keyhole of the storage room.
With a "click," the mask fit perfectly into the groove, and the six dots emitted a faint red light.
"What exactly do you want to do?" Kyogumichi stood up, looking coldly at Yoshida-sensei who was pouncing.
"You can't open it! The things inside will kill everyone!" Yoshida-sensei's eyes were bloodshot, like a beast that had lost its mind, "Nao… because it was opened back then…"
He didn't finish his sentence when the storage room door suddenly made a soft "humming" sound and slowly rose, revealing the pitch-black space inside.
A coldness even more intense than outside surged out, carrying a faint smell of blood.
Kyogumichi's flashlight beam shot in, illuminating a half-human-tall metal box, engraved with the same patterns as the mask, its surface covered with dark red stains.
Just then, Chitanda Eru's voice came through the earphones, with unprecedented clarity: "Okabara-san, I found it! The accident ten years ago wasn't an accident at all; Principal Sato locked students in the storage room to conduct experiments, and my cousin Nao was the only survivor!"
Kyogumichi suddenly turned his head to look at Yoshida-sensei.
The other party was slumped in the water, his eyes unfocused, mumbling: "It's my fault… if only I had called the police back then…"
The metal box in the storage room suddenly made a "click" sound, as if something inside had moved.
Kyogumichi gripped the entrenching tool in his hand, his gaze sharp as an eagle's.
He knew that the real secret was hidden in that box.
[Character: Chitanda Eru] [Bond Progress:11% → 15% (Triggered Event: Tacit Cooperation in Crisis) Points +440] [Event Evaluation:Her calmness and trust in a moment of crisis allowed your bond to take an important step] [Current Points:940]**
Although no prompt popped up on the system panel, Kyogumichi could clearly feel that the connection between him and Chitanda Eru had become incredibly solid.
No matter what they faced next, they would bear it together.
He took a deep breath and stepped into the storage room.
The metal box was right in front of him, as if waiting for the dust-covered truth to be revealed.