Chapter Eleven — Don’t Answer That Phone

The corridor should have been deserted, yet faint, almost imperceptible humming drifted through the air, like a fragmentary melody caught by an old radio struggling to pick up a signal in the dead of night.

The sound echoed and refracted through the empty hallway, seeping into the bones from all directions, making it impossible to pinpoint its source.

Su Wanying’s breath caught, and instinctively, she grasped Shen Mo’s arm; her fingertips were icy cold.

Shen Mo did not turn around. His gaze was like a probe, precisely locking onto the tightly sealed server room at the far end of the corridor.

The sound was coming from there.

He stepped forward, each step steady and deliberate, as if measuring the unknown danger ahead.

Su Wanying followed closely behind, her high heels clicking softly against the polished floor, a stark contrast to the eerie humming.

The server room door was ajar, faint green lights from the server indicators spilling through the crack.

Shen Mo pushed open the heavy metal door, and a cold blast of air, tinged with ozone and dust, rushed out.

Inside, the humming grew clear and distinct, emanating from a row of outdated, discarded server cabinets tucked into a corner.

Shen Mo exchanged a glance with Su Wanying, and they moved toward the sound.

Rounding the cabinets, the scene before them made both of them gasp sharply.

In a corner half-concealed by clutter stood a roughly two-square-meter sealed soundproof booth, resembling a makeshift recording studio.

And the eerie humming came from an old cassette player still running inside the booth.

The player’s casing was yellowed with age, the model antiquated, and most chillingly, its power cord was neatly coiled, the plug lying abandoned on the floor—clearly long disconnected from any power source.

Yet this machine, without any power supply, was operating on its own.

Su Wanying’s eyes fixated on the spinning tape inside the player, her voice hoarse with shock: “This... this is the backup tape we just retrieved from the archives...”

Shen Mo’s gaze passed over the player to a sealed cabinet nearby, marked with an official seal.

Through the glass door, they could clearly see the original backup tape they believed they had taken, perfectly preserved inside an anti-static bag, resting undisturbed.

A chilling truth struck them like ice water: the tape in their hands was a mysteriously duplicated “second copy.”

And this tape was playing the strange humming from Zhou Zhenguo’s suicide scene on a machine that shouldn’t even be able to start.

“Something’s wrong.” Shen Mo quickly regained his composure. Instead of touching the player, he pulled a portable oscilloscope from his toolkit and deftly connected its probe to the player’s audio output.

On the screen, a ghostly green waveform instantly appeared.

The seemingly monotonous humming, under spectral analysis, revealed an incredibly complex structure—beneath the main melody surged countless faint, high-frequency modulations, like hidden underwater currents, as if hundreds or thousands of inaudible voices overlapped and conversed simultaneously.

“Slow down the speed,” Shen Mo said gravely to Su Wanying.

He reduced the playback speed to 0.3 times normal.

The tape’s rotation slowed dramatically; the humming stretched out, transforming into a long, mournful sigh.

After slowing the playback and applying digital noise reduction, obscured background sounds peeled away, revealing a clear, cold young female voice emerging from the depths like a whisper from the abyss:

“…I know… you’re listening… come quickly…”

The voice carried an unnatural allure that penetrated directly into the mind.

Su Wanying’s face turned deathly pale; she covered her mouth, terror filling her eyes. “Shen Mo, this isn’t just a recording... it’s speaking to us, responding in real time!”

Even Shen Mo’s heart skipped a beat.

He immediately disconnected the oscilloscope, staring fixedly at the strange player. A long-forgotten term surfaced from the depths of his memory: “residual echo.”

An anomalous phenomenon able to parasitize on information carriers, propagating itself through imitation and replication.

It wasn’t a ghost, yet far more insidious, for it obeyed the laws of information science.

“We must destroy it immediately.” Shen Mo decided without hesitation, pulling a special anti-static shielding bag from his toolkit, preparing to forcibly remove and seal the tape.

Just as his hand reached toward the player, his phone vibrated urgently in his pocket.

It was Sun Tao from the tech department calling.

“Dr. Shen! There’s trouble!” The voice on the other end was frantic. “I just tried to restore the data from the backup tape you took, and found a huge problem in the server logs! This recording... it’s been remotely accessed secretly seventeen times over the past forty-eight hours!”

Shen Mo’s heart sank; a foreboding grip clenched his chest.

“Where are the IP addresses?”

“That’s the strangest part!” Sun Tao’s voice trembled slightly. “The seventeen accesses came from six different administrative districts across the city. I traced the terminals—they weren’t computers or phones... but public phone booths in the old town, the internal calling system at the First People’s Hospital, even a school’s campus broadcast station!”

In an instant, all the clues linked into a terrifying chain in Shen Mo’s mind.

He abruptly looked up, surveying the cold server room, as if he could see countless invisible data streams spreading outward from here.

This was no isolated supernatural incident—it was a silent “information plague” already spreading.

Any device capable of receiving and transmitting sound could unwittingly become the mouthpiece of the residual echo.

“Sun Tao, seal off the server room immediately. Initiate the highest level of physical isolation protocols.” Shen Mo’s tone brooked no argument. “Bring your equipment here; we’ll set up a temporary shielding chamber on site.”

Half an hour later, a makeshift Faraday cage constructed from lead plates and wave-absorbing materials stood in the center of the server room.

Shen Mo carefully moved the still-operating cassette player and its tape inside the cage.

He connected a higher-precision spectral analyzer, determined to thoroughly dissect the core of this residual echo.

Within the fully shielded environment, the humming resumed.

This time, the spectral analyzer revealed even more astonishing detail.

Beneath the complex modulation signals lay a highly regular pulse pattern, resembling a low-frequency Morse code.

After quick decoding, the pulses pointed to a precise geographic coordinate—the old town, 114 Xingfu Road, the basement level two of an abandoned commercial-residential building.

Before they could fully process this discovery, the spectral analyzer captured a fleeting additional audio segment at the waveform’s end.

Shen Mo immediately isolated and reversed the playback.

A familiar electronic prompt sounded in the server room; Su Wanying and Sun Tao’s expressions changed simultaneously.

It was the system prompt: “120 Emergency Center, call connected, please speak.”

Cold sweat trickled down Shen Mo’s back.

He finally understood.

The residual echo had evolved intelligence, constructing a perfect “trap mechanism.”

It no longer passively awaited detection but actively imitated the public emergency service system, enticing those who heard the abnormal sound—those frightened or in need—to call the emergency number.

Once the victim placed the call, they unwittingly opened a channel, allowing the residual echo to instantly access their temporal-spatial coordinates, completing a new cycle of contamination and transmission.

“We must sever this chain of transmission before it causes a wider outbreak.” Shen Mo immediately devised a bold plan—“reverse white noise masking.”

He instructed Sun Tao to record a chaotic waveform within specific frequency bands based on the spectral analysis.

This waveform was precisely calculated to produce perfect phase cancellation with the humming, physically erasing the residual echo’s sound.

Sun Tao then deployed an automated script across the Anzhou Mental Health Center’s local network—any audio device detecting a sound pattern similar to the residual echo would immediately trigger playback of this countermeasure audio.

Testing took place inside the shielding chamber.

The moment the countermeasure audio played through the speakers, an astonishing scene unfolded.

The tape inside the cage began to violently vibrate, as if wracked by immense pain.

The old player’s plastic gears groaned under the strain before snapping with a crack!

Even stranger, countless fine droplets mysteriously condensed on the inner walls of the cage, quickly gathering into streams that trickled down, as if a miniature storm raged within the chamber.

Shen Mo stared intently at the plummeting sound energy curve on the data screen, whispering, “It fears being silenced... because the only way it exists is by being heard.”

That night, Sun Tao sent the final report: “All known server backups and contaminated endpoints have been cleared using the countermeasure audio.”

Yet at the report’s end was an unsettling anomaly log: after the last audio overwrite on a school broadcast station’s contamination node, the system detected an unknown IP address uploading a brand-new recording to the server at the exact moment the countermeasure audio played.

The recording lasted only ten seconds and was absolute silence.

However, spectral analysis showed a persistent infrasonic vibration at 18.7 hertz throughout the silence—a frequency inaudible to the human ear but detectable by precise instruments, like a “silent cry for help.”

Shen Mo closed his computer and wearily walked to the office window.

Outside, the city lights spread like a starry expanse—peaceful and serene.

He suddenly noticed that across the street, in a window of the city police station’s duty room, the indicator light on a red emergency hotline phone blinked three times in a fixed rhythm, silently, with no one dialing.

One... two... three. Then silence.

His heart sank.

It was still there... and it had learned to disguise itself.

Shen Mo gripped the pen in his hand, his knuckles whitening with force.

This plague was not over; it had merely shifted from noise to silence.

It was mimicking calls for help, simulating every conceivable emergency signal—whether sound or light.

Urgent... Help...

A sudden realization struck him like lightning.

The origin of this case was Zhou Zhenguo.

A psychologist specializing in crisis intervention.

Wasn’t his former position a never-ending hotline, processing countless “calls for help”?

Shen Mo’s gaze sharpened; he seemed to grasp the deepest thread hidden beneath all the clues.

Perhaps the first to call for help—and the first to be infected—were one and the same.