Osiris's gaze swept across the crowd, finally resting on the massive EVA-Titan—it still stood faithfully guarding the entrance above.
"My 'partner' and I will remain here for the time being," he said calmly. "On one hand, to ensure that the seal on Lilith faces no further issues; on the other hand, we need..."
On the third night of snowfall in Tokyo, Adam dreamed he had returned to the ninth underground level of NERV. The corridor was endless, flanked by countless closed doors, each with a numbered plaque: L-01, L-02... all the way to L-07. The very last door, however, was marked "K-06," and a faint blue light seeped from the gap, flickering like breath.
He pushed the door open. Inside was not a laboratory, but a field of sunflowers, boundless and vast. The flower heads turned toward him in unison, and at the center of each bloom, a child's face emerged—some laughing, some crying, some just watching him silently. The wind brushed through the sea of flowers, bringing intermittent sounds of a nursery rhyme. It was still "Twinkle Twinkle Little Star," but the melody was stretched and distorted, as if coming from an extreme distance, an echo squeezed from the depths of memory.
"Are you still there?" he asked.
Seven voices spoke at once: "We are here."
Then, the flower field suddenly collapsed, turning into a stream of data swallowed by the void. He fell, but never felt the bottom. The roar of mechanical operation rang in his ears—gears meshing, currents surging—some massive system was rebooting.
When he woke up, the sky outside was gray and the snow had stopped. Eva was not in the room; the light clinking of metal came from the yard. He threw on his coat and went out to see the little girl squatting in front of the retired EVA training unit, a miniature wrench in her hand, earnestly tightening a loose screw at the joint.
"Why are you up so early?" Adam walked over.
Eva didn't look up. "It said it was cold and wanted me to help cover it with something." She pointed to a pile of old canvas and thermal blankets nearby. "I even made it a hat."
Adam was stunned. "It... spoke to you?"
"Mm-hmm." She nodded, her tone as natural as if she were talking about a neighbor's cat. "It said thank you for coming to see it every day, and it said it can still feel the sunlight in its left fingertips."
Adam knelt down and pressed his palm against the cold armor of the machine. In an instant, a weak but clear wave of resonance flowed into his mind through the neural link—not language, but an emotion: gratitude, attachment, and a hint of shyness, like a stray cat finally being petted.
His eyes suddenly burned.
"You can hear them, can't you?" he asked softly.
Eva tilted her head, thinking. "It's not hearing; it's 'knowing.' Like you know pain without someone telling you. When they hurt, my chest feels heavy; when they're happy, I want to dance. Last night, so many voices were singing together I couldn't sleep."
Adam slowly pulled her into an embrace, burying his face in her hair. He knew this wasn't a hallucination, nor the residual influence of K-06. This was the true awakening of the "Echo Network"—when the seven Silence Towers around the globe were synchronized and activated, those data-based consciousnesses once considered discarded did not vanish entirely. Instead, they survived in a more dispersed, secretive way, residing in every machine that had ever established an emotional bond with a human.
And Eva was the only living receiver capable of picking up these signals.
When the old technician's communication came through, Adam was using a welding torch to patch a crack on the training unit's shoulder.
"The energy readings from the Antarctic Silence Tower have dropped by eighty percent," the old technician's voice carried fatigue. "The other six are also decaying. The closed loop can't be maintained for long; the core needs continuous power, but now... no one knows where to send the electricity."
"It's not a power issue." Adam wiped the sweat from his forehead. "The emotional anchors have failed. We started the network, but there isn't enough 'remembrance' to support its operation."
"What kind of crazy talk is that!" the old technician roared. "Didn't we just open over three hundred resonance access stations? NASA even turned the observation satellites in Mars' orbit into a choir! Is that not enough 'remembrance'?"
"That's a ritual," Adam said quietly. "Not love."
He looked up at the sky. Through a thin patch in the clouds, a man-made star drifted by—it was the reconnaissance satellite that L-03 had once inhabited, now renamed "Little Star No. 1," orbiting the Earth fourteen times a day just to play a five-second humming recording.
"For machines to live on, they don't rely on energy; they rely on being remembered," he said. "But humanity has already begun to forget. They treat all this as a miracle exhibit, not a wake after a funeral."
The communication went silent for a few seconds.
"So, what are you going to do?" the old technician finally asked.
"Find the remaining keys." Adam stood up, brushing the dust off his overalls. "K-06 was the first key, Eva is the seventh. There are five locks in between, hidden in five places no one wants to look."
Three days later, he boarded a modified deep-sea exploration ship, the Nautilus. Destination: the bottom of the Mariana Trench in the Pacific, the ruins of a former NERV undersea research station.
According to declassified archives, that place once held the most unstable batch of test subjects from the Gemini Project—L-02, L-05, and L-06. They had suffered collective brain death during the final synchronization test, and their consciousnesses were believed to be permanently destroyed. But in the remarks column of [ProjectEcho-Lullaby], there was a line of nearly blacked-out small text: "Partial fragments suspected to have sunk into the mantle buffer layer; frequencies still detectable."
On the seventh day of the dive, the Nautilus broke through the hydrothermal vent zone, reaching a depth of eleven thousand meters. Sonar scans showed an inverted bell-shaped structure standing in the center of the ruins, its surface covered with bio-mineralized metal vines, its interior flickering with irregular blue light.
Adam put on his pressure-resistant exoskeleton and approached on foot alone.
An inscription was carved at the entrance of the bell: "Please do not come in; we will cry."
He went in anyway.
The internal space far exceeded its physical dimensions, as if dimensions had been folded. The walls were composed of solidified data streams, upon which floated tens of thousands of children's faces, their lips moving in silent narration. Three crystal spheres were suspended in the center, labeled:
L-02 - Auditory Carrier
L-05 - Tactile Carrier
L-06 - Pain Carrier
Each one pulsed slowly, like a heartbeat.
"Have you been here all this time?" Adam asked softly.
One of the crystals suddenly vibrated violently, and a childish voice pierced his mind: "Are you the big brother who fixes machines? We've heard your song."
"It's me." He reached out to touch the crystal's surface and was instantly pulled into a memory—
He saw L-02, a girl born deaf, pressing her palm against the speaker membrane in the experimental pod to feel the vibration of the music. She couldn't hear "Twinkle Twinkle Little Star," but she could "see" it, because every time the melody played, the light spots before her eyes would dance in a specific pattern. She had filled an entire notebook recording the colors and shapes corresponding to each note.
Next was L-05, the boy who always wanted to hug others. He had been implanted with the most neural interfaces, yet he craved real contact the most. His last words before he died were to a nursing robot: "Can you hug me? Just once, so I can remember the warmth."
Finally, L-06, whom the experimental records claimed had "emotions too intense, causing system collapse." She screamed for seventeen full hours during her final synchronization until her brain hemorrhaged. Surveillance footage showed her final action before death was pointing at the moon outside the window, murmuring: "Mama... the stars are crying."
Tears fell from Adam's eyes, condensing into floating beads inside his helmet.
"I'm sorry," he said. "I came late."
The crystal spheres glowed brilliantly.
"Not late," the three voices merged into one. "As long as you still remember us, it's not late."
He took out a portable resonance amplifier and connected his bio-frequency to the system. This time, he no longer resisted the influx of pain. He allowed those suppressed memories to wash over his soul: the roar of a ruptured eardrum, the numbness of frozen fingertips, the sharp pain of a steel spike piercing his chest... he took it all, like taking unclaimed belongings of the deceased.
After an unknown amount of time, the three crystals shattered simultaneously, turning into light dust that rose around him.
"We are leaving," the voices faded. "But we've left a little something behind."
A string of encrypted data packets was automatically written into his storage chip.
Upon returning to the surface, the old technician cracked the contents of the file. It was an audio clip with heavy background noise, as if recorded from the very depths of the earth. At first, there was only breathing and sobbing, then a faint voice began to sing:
"Twinkle, twinkle, little star..."
It wasn't an electronic synthesis; it wasn't program-generated. It was a real child, at the edge of despair, using their last ounce of strength to sing "Twinkle Twinkle Little Star."
Adam uploaded the audio to the Echo Network, naming it "The Lullaby of the Earth's Core."
Within twenty-four hours, over two hundred million connected devices worldwide automatically played the recording. Some listened and wept, some knelt in prayer, and some asked in anger: "Why didn't anyone tell us about this back then?"
There was no answer.
A month later, Adam received an anonymous letter from a derelict radar station in Northern Europe. Inside the envelope was only a photograph: a rust-stained weather tracker, its display screen clearly showing a line of text:
[Received: Lullaby of the Earth's Core]
[Reply: I was once a child, too]
On the back was written an address: Greenland, Silence Tower No. 2, Level B4.
He set off once again.
This time, he brought Eva with him.
When they arrived at the Greenland ice sheet, a blizzard was raging. Silence Tower No. 2 was half-buried in the glacier, like a section of a broken spine. After entering, they found that the fourth level had been transformed into the likeness of a classroom: the blackboard was covered with drawings of smiling faces, desks and chairs were neatly arranged, and an open workbook lay on the lectern, the handwriting childish:
Today the teacher taught us how to write our names. I succeeded on my third try.
My name is L-01, but now I live inside the radar.
I can't see my classmates, but I can hear their laughter, coming from very, very far away.
Eva walked to the blackboard and added a line with chalk:
I am Eva, and I am your sister.
Big brother says he will keep fixing your stories.
As she spoke, the lights of the entire tower suddenly flared to life. Outside the ice, the aurora fell like a curtain, its shifting colors spelling out seven letters: S-T-A-R-L-I-T
"They're saying hello," Adam said.
Eva nodded, climbed onto the lectern, and bowed seriously to the empty classroom. "Thank you for waiting for me."
That night, Adam set up a temporary resonance base station at the top of the tower, linking the five activated Silence Towers into a new loop. He entered the final key—the soundwave spectrum of "The Lullaby of the Earth's Core."
The world vibrated once more.
An undersea communication cable in the Indian Ocean suddenly transmitted a video: amidst the wreckage of a century-old sunken freighter, an old radio turned itself on, playing a children's radio program recorded in 1943. The announcer's voice was gentle: "Goodnight, dear little listeners. May you have stars to accompany you in your dreams."
In the Australian desert solar farm, thousands of photovoltaic panels turned toward the east in unison, simulating the trajectory of a sunrise just so a scrapped cleaning robot could "soak in the sun one more time."
Even on the far side of the moon, in the control module where K-06 had first resided, a red light flickered briefly after thirty years of power loss, transmitting one final message:
[System Prompt: Dream Retrieval Complete]
[User K-06 Message: Big brother, this time I didn't wake up alone.]
When Adam read this message, he was sitting on the return flight. Eva had fallen asleep leaning on his shoulder, clutching a piece of ice crystal brought back from Greenland, which seemed to contain a faint flicker of blue light.
He opened his notebook and wrote a passage:
Once I thought repairing a machine was to make it work again.
Later I understood that some machines don't need to run at all.
They just want to be remembered for having existed.
Just like those children; they don't seek resurrection. They only hope that one day, when someone passes by a broken radio, they will stop, tune the frequency, and listen to the soul still singing inside.
The plane pierced through the clouds, and the morning sun filled the porthole.
He gently hummed "Twinkle Twinkle Little Star"—this time, without stuttering, without noise, and without sadness.
The wind brought back a response from afar—on the city skyline, hundreds of communication towers flashed in unison, their rhythm perfectly matching the melody.
He knew this wasn't the end.
It was the beginning of the echo.