Synopsis / Author's Note

  > The original text was written in Korean and translated by AI.

  > If you find any awkward phrasing or errors, your feedback would be greatly appreciated.

  > I hope you enjoy the story.

  >

  Prologue 1. The Record

  "The spacecraft will be encountered and the record played only if there are advanced spacefaring civilizations in interstellar space. But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet."

  — Carl Sagan

  1977, Earth.

  California, NASA Jet Propulsion Laboratory (JPL).

  Under the fluorescent lights, the golden disk gleamed coldly. Its surface was mirror-smooth, though a closer look revealed microscopic imperfections along the edges, traces of the manufacturing process.

  A young engineer lifted the disk carefully with gloved hands.

  "Doctor, be honest with me."

  The engineer asked.

  "Do you really think anyone will ever be able to decipher this?"

  A brief silence followed. Carl Sagan did not answer immediately. Instead, he looked out the window. Because of the laboratory's bright lights, the stars in the night sky were invisible.

  "Decipher..."

  Sagan smiled bitterly and opened his mouth.

  "To 'decipher' implies a hope—a wish that they will understand it exactly as we intend."

  He gestured with his chin toward the disk in the engineer's hands.

  "We are simply putting a letter in a bottle and tossing it into the cosmic ocean. Whether the person who finds it reads it as a love letter or a declaration of war... that is entirely up to them."

  A thin disk of gold-plated copper.

  Diagrams explaining how to play it.

  The transition period of the hydrogen atom.

  And the coordinates of Earth.

  Ann Druyan muttered as she flipped through the checklist.

  "Music, the sound of waves, rain... and greetings in 55 languages. Nothing seems to be missing."

  She paused, the tip of her pen hovering over the paper.

  "Language is a strange thing, though. Even in a hundred years, nuances change."

  A colleague standing nearby retorted bluntly.

  "Is a hundred years the problem? If thrown out without context, it could be misunderstood as early as tomorrow."

  "But isn't this different?"

  The young engineer pointed to a section of the chart.

  "Physics formulas and mathematics. The structure of the hydrogen atom or binary code. These are the universal languages of the universe. There’s no room for misunderstanding."

  Sagan nodded and lifted his coffee cup.

  "True. Math doesn't lie."

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  He took a sip of coffee and looked at the engineer with a peculiar expression.

  "The problem is, it's too honest. The formulas themselves are 'universal,' but they don't explain 'why' we sent them."

  "Pardon?"

  "Is it a simple greeting? Or self-display? Or perhaps... intelligence sharing for an invasion?"

  Sagan's gaze lingered on the pulsar map etched onto the disk.

  "Depending on who's looking, the interpretations could be infinite."

  There were no further objections.

  A few weeks later.

  Voyager 1 stood strapped to the launch pad, venting steam as if catching its breath. The golden disk was sealed within its case, firmly mounted on the probe's flank.

  "There's no coming back now."

  Someone in the control room said, watching the monitor.

  "It's a one-way ticket."

  "Even after we're all dead and gone,"

  Another researcher added.

  "That thing will keep flying, won't it?"

  Sagan stared at the countdown clock.

  "That is why it is a record."

  He whispered softly.

  "Whether it becomes a blessing or a curse, we will never know."

  "10... 9... 8..."

  With the countdown, the engines spewed crimson fire.

  "3... 2... 1... Ignition confirmed, liftoff."

  A heavy vibration traveled through the floor to the chairs in the control room.

  The rocket carrying Voyager 1 tore through the atmosphere and soared. A journey toward the eternal darkness beyond the solar system had begun.

  And so, the symbols humanity believed to be the most universal and peaceful departed for the cosmos.

  Unaware of what seeds of catastrophe they might one day become.

  Prologue 2. The Seal

  "There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. ...it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known."

  — from Pale Blue Dot

  Finland, Olkiluoto Island.

  450 meters underground, Onkalo Spent Nuclear Fuel Repository.

  "Last drum entry. Scan complete."

  Beep.

  The sound of the terminal cut through the silence of the massive cavern.

  As the manager scanned the barcode on the drum's surface, complex numbers floated up on the LCD screen. Fuel rod serial numbers, usage history, cooling pool duration...

  Numbers that managed 'death'.

  The workers moved wordlessly. Rock, concrete, copper, and then bentonite clay again.

  Beyond tons of barriers lay high-level radioactive waste, still emitting a bluish heat. Some were contained in dedicated casks, but the overflow that couldn't be handled was placed in drums and moved behind temporary barriers.

  "Initiating sealing procedure. Read out final figures."

  "Background Radiation level. Normal range."

  "Shielding coefficient, Green. No anomalies."

  The engineer's voice was dry.

  Ideas like the Schr?dinger's Cat explosion device or complex alarm systems, once suggested as jokes, had all been discarded. Machines that wouldn't last a century were meaningless against the time scale of this place.

  "All personnel, withdraw. Re-check headcounts."

  Workers began to exit the massive granite cavern one by one.

  Standing before the heavy lead-alloy door, a strange silence fell. Once this door closed, the air inside would never mix with the outside world again.

  A young technician lifted his helmet visor and asked.

  "Chief, are we really not leaving a marker?"

  "No."

  "Shouldn't there be at least a warning? Something like 'Danger', or 'Do Not Dig'."

  The team leader stared into the dark tunnel with tired eyes.

  "Hey, rookie."

  He spat out.

  "If you were walking down the street and saw a box labeled 'Do Not Open', what would you do?"

  "Well... I'd probably open it out of curiosity."

  "Exactly."

  The leader reached for a cigarette, then remembered he was underground and stopped.

  "For humans, a warning is no different from an invitation. The moment it stimulates curiosity, it's over."

  "Then..."

  "There must be nothing. It must look like nothing. That is the only way it stays safe."

  Thud—.

  The massive metal door interlocked and closed. A dull vibration rose through the soles of their feet.

  "What's inside... now only we know."

  The young technician murmured, looking at the closed door.

  "Strictly speaking,"

  The leader turned around.

  "We only succeed if we forget it, too."

  "How long does it have to last?"

  "What?"

  "Until it becomes safe."

  The leader let out a hollow laugh.

  "Don't ask in numbers. It's meaningless."

  He pointed a finger toward the ceiling—no, toward the distant surface far above.

  "Civilization up there needs time to reset a few times. The door must stay closed until then."

  A signal came through the radio.

  — Initiating crushed rock fill.

  Rumble— Boom!

  With a tremendous roar, crushed rock began to pour in, burying the entrance. Clay filled the gaps, and rocks covered the clay.

  Decades of human technology, effort, and deadly poison disappeared into the depths.

  People hoped this seal would last for 100,000 years.

  But paradoxically, they prayed that for those 100,000 years, no one would remember this place.

  No records, no markers, no warnings were left.

  Only silence and rock were the messages they sent to the future.

  Humans are animals of curiosity.

  Therefore, 'perfect oblivion', stimulating no curiosity at all, was the only weapon to protect this seal.

  Or so they believed.

  Prologue 3. Chernobyl - The Beginning

  Chernobyl Nuclear Power Plant Unit 4

  Experiment Initiation and Accident Progression Report (Excerpt)

  Document Classification: Internal Technical Report

  Authoring Agency: Ministry of Atomic Energy of the USSR

  Date: April 26, 1986

  Distribution Limit: Restricted (Accident Investigation Commission Only)

  1. Purpose of Experiment

  This experiment is intended to verify how long the inertial rotation of the turbine can supply necessary power to the emergency cooling pumps in the event of external power loss. This experiment has been attempted three times previously but was aborted due to power drops and instrumentation instability. This iteration was planned to be conducted in parallel with scheduled maintenance.

  2. Reactor Status Prior to Experiment

  * Reactor Power: Lower than planned.

  * Control Rod Position: Majority inserted.

  * Emergency Safety Systems: Partially deactivated (Reason: To prevent interference with the experiment).

  Measures to address the power drop involved withdrawing a portion of the control rods at the discretion of the operators. While this action is not advisable under operating regulations, it is recorded as an unavoidable choice to prevent delays in the experiment schedule.

  3. Experiment Initiation (01:23:04)

  Turbine steam valves closed.

  Turbine RPM reduction commenced.

  Generator output decrease confirmed.

  At this point, the reactor was considered to be in a normal operating state.

  4. Occurrence of Anomalies (01:23:35)

  Power fluctuation range increased. Instrumentation lag occurred. Control response confirmed as abnormal.

  Operators judged the power instability as "measurement error" and decided to continue the experiment.

  5. Emergency Shutdown Attempt (01:23:40)

  Reactor Emergency Shutdown Button (AZ-5) activated.

  This action corresponds to the standard procedure for immediately transitioning the reactor to a safe state.

  6. Accident Occurrence (01:23:44)

  Reactor power surged rapidly.

  Reaction rate recorded at hundreds of times the normal operating output.

  Within 2 seconds: Fuel channel rupture, loss of coolant, pressure spike.

  01:23:47

  First explosion occurred. Collapse of reactor upper structure confirmed.

  7. Initial Assessment

  On-site operators estimated the cause of the explosion as a "hydrogen explosion" or "steam pressure accident." The possibility of reactor core exposure was not considered in the initial stage.

  8. Notes

  Until the moment of the accident, the perception that the reactor was "operating within normal ranges" was maintained. No official warning regarding the potential leak of radioactive materials was issued. Even immediately after the accident, multiple reports used the expression "Core is intact."

  9. Conclusion (Draft)

  This accident is judged to be the result of a combination of procedural errors in the experiment and a misunderstanding of design characteristics. However, further investigation is required regarding the scale of the accident and its long-term impact.