Yu Sheng had only said that the extra rooms on each floor were dangerous and that they should get away from them immediately. He’d never mentioned how one could get in intentionally.

He probably never imagined the stair-climbing team would end up in a predicament where they had no choice but to enter an extra room.

"Jiang Yang, don’t you have a key that can open any door...?"

Zhao Zhenjia recalled Jiang Yang mentioning this Supernatural Artifact before.

Jiang Yang stared at the blank wall next to Room 524:

"I do have a key like that."

"But the problem is, there has to be a door for me to open one."

"Right now, Room 525 doesn’t even exist. A master key can’t open it."

Lan Chu suddenly took off, sprinting away from them.

Gao Tian asked instinctively:

"Where are you going, Lan Chu?"

Lan Chu glanced back at him as she ran:

"Run between the third and fourth floors a hundred times, and the extra room will appear."

Gao Tian asked, bewildered:

"Who told you that?"

He instinctively wondered if Lan Chu possessed some special Supernatural Artifact.

Lan Chu replied:

"Nobody."

"It’s a setting I just came up with."

Watching Lan Chu’s figure recede into the distance, Gao Tian couldn’t be bothered to stop her. ’She’s lost her mind again.’

With every second that passed, the threat of death grew for Xia Ta inside Room 525. For all they knew, she could already be dead, and the stair-climbing team would be waiting out here for nothing.

Just when the situation was already critical, things took a turn for the worse.

Jiang Yang, who was at the end of the hallway, suddenly turned his head slowly. With a dazed look in his eyes, he said something baffling:

"Who?"

"What?"

No one knew who he was talking to; both Zhao Zhenjia and Gao Tian were completely bewildered.

Jiang Yang looked toward the other end of the hallway, his gaze growing distant. It was as if Xia Ta’s disappearance no longer mattered. He brought a finger to his lips in a hushing gesture.

"Be quiet."

"Can’t you hear it?"

"There’s a sound... of a hammer striking the walls in this corridor."

Those words struck them like a sledgehammer to the chest.

Of course, they remembered the third rule Yu Sheng had written—the most important one of all.

If the sound of a hammer striking the walls is heard in the corridor, leave immediately.

Immediately. Instantly. This rule superseded all others.

With the sound of the hammer, their team really had to retreat. But doing so would mean abandoning Xia Ta on the fifth floor.

Even if Xia Ta made it out of the Children’s Home alive, an even more terrifying, rules-based horror would be waiting for her in the hallway.

This was no small matter. The color drained from Zhao Zhenjia’s face.

"Are you sure? Why can’t I hear anything?"

Jiang Yang’s senses were exceptionally sharp. Under normal circumstances, the team would have trusted him without question.

Gao Tian immediately pressed his ear to the floor, trying to pick up the inaudible sound through the vibrations. But he still heard nothing.

The corridor was eerily silent, save for the sound of Lan Chu’s approaching footsteps as she completed a lap and ran back. There was no hammering sound whatsoever.

He, too, began to wonder if Jiang Yang had been mistaken.

Seeing the doubt on their faces, Jiang Yang said grimly:

"Trust me, the hammering has definitely started..."

"It’s just very distant at the moment, still a long way off."

"Perhaps we still have a little more time to wait for Xia Ta."

Gao Tian said:

"Let me pull you into the Mirror World. Maybe we can evade the rules-based horror in there."

"In any case, it’s safer than waiting out here."

A low female voice spoke up:

"Didn’t I tell you all to return to the third floor and await orders?"

"Jeez. You heard the hammering and you’re still here? Are you trying to get yourselves killed?"

CLICK.

The sound of a door opening and then closing.

At the end of the hall, next to Room 524, a door materialized and was pushed open. A figure slowly emerged. The door swung shut behind her, instantly melting into the wall and vanishing without a trace.

The extra room, 525, had appeared and vanished in the blink of an eye. But what astonished Gao Tian even more was the person who had stepped out of it: Xia Ta.

She was covered in blood, her face etched with exhaustion. Her right arm seemed to be broken, dangling limply like a doll’s. But Xia Ta’s will was made of steel; she paid her ruined arm no mind. In her left hand, she clutched a glass container filled with strange, squirming black specks.

It was impossible to make out what they were without getting closer.

"Sister Ta!"

From the other end of the hall, a panting Lan Chu rushed over. The moment she saw Xia Ta emerge from Room 525, she was stunned by the rule she had just fabricated:

"I never thought the setting I added would be so useful."

"I hadn’t even finished a hundred laps—I was only on my first—and Room 525 opened on its own."

Looking at Xia Ta, who seemed to have returned from the dead, Zhao Zhenjia had a thousand things he wanted to say. But in the end, they all boiled down to a single sentence:

"As long as you’re back. We were all waiting for you."

Jiang Yang said nothing. This wasn’t his first mission with Xia Ta, and it wasn’t the first time she had gone off on her own, diving deep into the heart of the danger to eliminate the main threat by herself.

The current apartment manager was, in truth, a rather unreliable person who just did whatever she pleased. Jiang Yang had gotten used to it long ago.

Xia Ta’s gaze landed on Gao Tian.

"Thank you, Gao Tian."

"Your sudden reminder, right before I was pulled into the Children’s Home, gave me the inspiration I needed. It helped me figure out the killing pattern and the only path to survival."

Gao Tian asked:

"What were the rules in that strange room?"

He really couldn’t wrap his head around it. A big, empty room full of toys, with no ghosts or even people in sight. How could sitting down and playing with toys possibly be the path to survival?

Xia Ta replied calmly:

"Ah, it’s a long story. This isn’t the place for it. We can talk once we’re downstairs."

"I paid a small price for it, too—a broken arm."

She held up her left arm, displaying the glass container in her hand.

"After I found the path to survival and defeated them, I sealed those ’filthy things’ from the room in this container. They’re completely trapped now."

"They were once my parents. Not anymore."

"The Children’s Home incident is finished. There will be no more new victims, no more accomplices for the fifth-floor ghost."

And just like that, the Children’s Home incident—the one that wiped out all the building’s residents seven years ago—was single-handedly resolved by Xia Ta, at the cost of one arm.

She spoke of it so casually, as if it were nothing remarkable.

"We have to hurry back to the second and third floors to deal with the aftermath."

"Deep inside the Children’s Home, I found over twenty beds meant for living children. But not a single child was in them."

"That means while we were coming upstairs, the ’living’ children from the Children’s Home came out in full force. They’ve gone down to the second and third floors to find the residents who still don’t know the truth."

"Those residents have absolute faith that the apartment is safe. When they’re confronted by these children—who have lived in the Children’s Home for so long and are brimming with resentment and malice—I doubt even the adults can fend them off."

There was another, more important reason why the team had to retreat immediately, one that Xia Ta left unsaid—

From the distance came a low, heavy hammering. THUD. THUD. Though the source was still far away, the terrifying pressure it radiated was immense. The walls of the entire corridor began to tremble faintly.

Along the corridor, the sound of locks being thrown could be heard from behind countless doors. It was as if the floor’s original inhabitants, who had never once shown their faces, were utterly terrified by the approaching hammer.

’So it’s here. The most dangerous of Yu Sheng’s six rules-based horrors.’

Jiang Yang’s senses were proven right once again.

A moment ago, Zhao Zhenjia and Gao Tian had wanted to argue with Jiang Yang, but it was only because they were subconsciously looking for an excuse to stay and wait for Xia Ta.

Now that Xia Ta was back, there was no need to remain on the fifth floor.

"This way, let’s take the stairs down."

Led by Xia Ta, the group hurried to the entrance of the stairwell.

But just as she was about to step down, Xia Ta froze. Her brow furrowed, as if she’d noticed something.

"Wait. Don’t go this way yet."

Lan Chu, arriving right behind them, had already put one foot forward and had to snatch it back abruptly.

"What’s wrong? Did you sprain your ankle?"

Jiang Yang, who was standing at the edge of the stairs, also realized something was off.

"The stairs... there are 14 steps."

"These stairs are wrong. We’ve triggered Yu Sheng’s fourth rule again."

Normally, there are only thirteen steps. If a flight of stairs has fourteen, it means the stairwell is temporarily unusable and must be vacated immediately.

Gao Tian, not wanting to take any chances, counted them himself. Sure enough, there were fourteen steps.

Xia Ta was truly meticulous. Even after a life-and-death ordeal in the Children’s Home, she remained incredibly cautious, her perception of any anomaly in her surroundings as sharp as ever.

Behind them, the sound of the hammer striking the wall grew closer, the vibrations nearly deafening. An indescribable, immense terror was about to descend upon them.

"Get into the Mirror World with me! We’ll use it to get back to the third floor."

The situation was critical. Zhao Zhenjia slammed the full-length mirror down with a CLANG. Gao Tian thrust a hand into its surface, ready to pull himself in first, followed by the rest of the team one by one.

BOOM—

The distant hammer struck the wall again, a heavy blow. A massive shockwave ripped through the corridor like a small hurricane, so powerful that the group could barely stay on their feet. The full-length mirror, their only one, was instantly shattered by the blast, exploding into a million glittering fragments. It was nothing but a pile of debris now, no longer an entrance to the Mirror World.

Even more horrifying, Gao Tian’s arm, which was already inside the Mirror World, was severed when the entrance shattered. With a sickening SNAP, the limb was torn from his body, and blood sprayed everywhere.