10: A letter

October 3, 2025, the third day of the National Day holiday.

The streets were filled with the hustle and bustle of the holiday, but this liveliness failed to penetrate the study in Professor Liu's home, which was submerged in a sea of books.

Professor Liu did not take advantage of this rare long holiday to spend time with his family or go out for a trip, unlike most of his colleagues at the research institute.

The astronomical tsunami three months ago, known as the "HIAL-137 Incident," had completely disrupted the peaceful scientific life he should have been enjoying in his twilight years.

An unprecedented sense of urgency and responsibility acted like an invisible gravitational force, firmly binding him to his desk.

He was writing a paper—a paper he believed might be the most important and unconventional of his academic career.

On the monitor, the document title was clear and striking: "On the Various Possibilities of Third-Kind Contact and Countermeasures."

Three months ago, this was a topic that would only appear on science fiction enthusiast forums and amateur UFO symposiums.

But now, it had become the highest priority and most confidential topic among the upper echelons of all major world powers and top think tanks.

"...Therefore, for two races with different thoughts, different structures, and perhaps even completely different evolutionary methods to achieve effective communication, there must be a common system that is mutually recognized and cannot be misinterpreted."

"Given the current level of technology, this system can only be basic physics and mathematics..."

After typing another line on the keyboard, Professor Liu rubbed his tired, aching eyes and leaned back in his chair.

He took off his reading glasses and looked at the clear sky outside the window.

His thoughts, however, involuntarily drifted back to the lecture he had held at the university a few months ago.

For some reason, he suddenly remembered the young man who had fallen asleep during his lecture but answered his questions fluently after being called upon.

He could no longer remember the student's name, only his exceptionally bright eyes and the calmness and certainty that transcended his age when answering the questions.

The student's answer regarding how to conduct the first information exchange with an alien civilization was clear in its reasoning and logically rigorous; some of his points even coincided perfectly with the paper he was writing.

Professor Liu could be certain that the graduate students studying for their doctorates under him might not have been able to answer so perfectly in that impromptu situation.

It did not sound like he was answering a hypothetical question, but rather... stating an established fact.

"Perhaps he was just an astronomy enthusiast..." Professor Liu shook his head and smiled self-deprecatingly.

What was wrong with him? To be dwelling on a student he had never met before.

He attributed this to the excessive mental stress he had been under recently, which had caused some kind of empathy effect.

He decided not to trouble himself any further and planned to turn off the computer, go to the living room to make a cup of strong tea, and take a nap on the sofa.

However, the moment his finger was about to touch the shutdown button, something strange happened.

His email client, the program window he had clearly minimized, popped up automatically without any warning and instantly occupied the entire screen.

An email that had just arrived was lying quietly at the very top of the inbox.

Its subject line was highlighted by the system in a glaring, bright red color he had never seen before, as if emitting a silent scream, forcing him to focus his gaze upon it.

Professor Liu's brow furrowed instantly.

A virus? Or some new type of hacker attack? He subconsciously grabbed the mouse, preparing to force the program to close.

But his gaze was firmly locked onto the sender's name and the email subject.

【Sender: the guide】

【Subject: A Supplementary Explanation Regarding HIAL-137, and a Key】

the guide...

This term seemed to carry some kind of mysterious magic, causing Professor Liu's heart, which had weathered many storms and had long since become unperturbed, to jump violently.

He hesitated for a moment, but finally moved his finger away from the close button and clicked on the email.

The content of the email appeared before his eyes in an extremely concise, calm, and emotionless layout.

【To: Professor Liu, and all those who look up at the starry sky

You have named the star system 13 light-years away HIAL-137 and have shown great confusion toward it.

This document is intended to partially correct and supplement your existing observation data.

First is the precise situation regarding the HIAL-137 Galaxy.

Planetary Atmosphere (with Earth's standard atmospheric pressure as 1):

「Third Planet (Gaia Planet): Nitrogen 75.4%, Oxygen 23.1%, Argon 0.9%, Water Vapor and Trace Gases 0.6%. Atmospheric Pressure 1.08. Average Surface Temperature 17.3℃.」

「Fourth Planet (Gaia Planet): Nitrogen 68.2%, Oxygen 28.5%, Carbon Dioxide 1.5%, Others 1.8%. Atmospheric Pressure 1.21. Average Surface Temperature 9.8℃.」

「Fifth Planet (Gaia Planet): Nitrogen 81.0%, Oxygen 15.3%, Methane 2.1%, Others 1.6%. Atmospheric Pressure 0.89. Average Surface Temperature -3.5℃.」

(Note: The accuracy of the above data has excluded instrument errors and represents absolute true values.)

Next is regarding the "Anomalous Structure" (Giant Space Dock).

「Precise Dimensions: Maximum diameter 974 kilometers, total mass approximately 5.34 x 10^15 kilograms.

Main Constituent Material: "Crystallized-Neutronium Composite Armor." This is a high-density material formed by stably embedding neutron-state matter into conventional metal lattices at the atomic level. Earth's current technology is not yet able to understand its principles.」

Finally, there is a key serving as a "measuring stick."

「Simple observation cannot shorten the distance between civilizations. To enhance your understanding, we have attached a set of relatively basic, obsolete technical data.

Perhaps you can regard this as a measuring stick to gauge the gap between both sides.

This "gift" contains three parts, which are prerequisites for each other and none can be missing:

【Foundational Theory of Microscopic Materials Science】: Content: Contains the theoretical foundations and mathematical models for precisely manipulating and constructing matter at the atomic level. This is the prerequisite for realizing the subsequent two technologies. Without this technology, you cannot manufacture materials capable of withstanding the corresponding energy densities and stresses.

【Controllable Cold Nuclear Fusion Reactor】: Content: A miniaturized, high-efficiency continuous fusion energy core. Its principle is not the magnetic confinement of high-temperature plasma like the "Tokamaks" or "Stellarators" you are currently researching, but rather directly compressing and igniting deuterium-tritium fuel through a high-frequency gravitational field. It can provide stable and massive energy for the subsequent thrusters.

【Third-Generation Ion Thruster】: Content: A high-specific-impulse, high-efficiency sub-speed of light propulsion technology. Its core is confining heavy metal working fluid (it is recommended to use "Osmium") in a strong magnetic field and accelerating it to be ejected at speeds approaching the speed of light. Although it is almost useless for interstellar travel, it may save a significant amount of time for your current exploration within the Solar System.

Relevant technical data documents are in the attachment.」

—the guide】

Professor Liu read the entire email word by word.

When he finished reading the last word, he found that he was unable to breathe.

His first reaction, like that of any rational scientist, was: This is a hoax.

An extremely clever, extremely malicious, earth-shattering hoax concocted by some top physicist or research team!

How could they possibly know the atmospheric composition of those planets with such precision?

The James Webb Telescope had already exhausted its capabilities, and yet it could only reach a vague conclusion with a massive margin of error.

Yet the data in this email was accurate to one decimal place!

And that "Crystallized-Neutronium Composite Armor," the term sounded like it was copied directly from a science fiction novel!

But...

Professor Liu's gaze was fixed intently on the icons of the four attachments at the bottom of the email.

Three of them were not text documents, but three massive, encrypted data packages.

The file sizes were displayed below the icons, each exceeding 1TB; only the fourth attachment was small in volume, like a normal document.

Would a scammer spend such massive effort to forge three such enormous data packages?

His hand moved toward the mouse uncontrollably.

Reason was warning him frantically: Do not click! This could be some kind of super virus that would destroy his computer in an instant and steal everything he had!

But his academic instinct, his curiosity that had pursued the truth for a lifetime, was like an invisible giant hand that pressed firmly on the back of his hand, forcing him to click.

He clicked on the first attachment: 【Foundational Theory of Microscopic Materials Science】.

No virus, no attack.

What popped up was a professional reader that required an authorization key to open.

And in the preview window of the reader, he saw the content of the first page.

They were rows of neat, never-before-seen mathematical symbols, constructing a theoretical framework he had never heard of.

Those formulas, strange yet elegant, seemed to contain the deepest harmony and order of the universe.

Although he could not immediately understand their full meaning, his professional intuition, which had been immersed in physics for nearly fifty years, was screaming at him—these are real!

These formulas are self-consistent! They can solve several unresolved paradoxes in current quantum mechanics and materials science!

Professor Liu felt his worldview being completely crushed at this moment, and then reassembled in a more magnificent and glorious way.

This email was not a hoax.

Or rather, even if it were a hoax, the "person" capable of creating it would possess wisdom and knowledge that already far surpassed the scope of Human Civilization!

Trembling, he clicked on the second and third attachments.

The same preview window, the same groundbreaking theories and design blueprints shining with the light of wisdom.

He understood the meaning of that sentence in the email—a key serving as a measuring stick.

The other party was not showing off their military might, but using a more fundamental and irrefutable way to demonstrate the gap between them—the gap in knowledge.

An "obsolete technology" they threw out casually was enough to lead Human Civilization into a new era.

This key led to a future among the stars and the sea.

But at the same time, it was also a warning bell.

A death knell that rang suddenly at your bedside in the middle of the night.

It was telling you: You are not alone. And, you are extremely backward.

Immediately after, Professor Liu clicked on the fourth attachment. Inside this attachment was only a text document containing a brief introduction to a technology called the 【Fifth-Generation "Phantom" Stealth Force Field Generator】, and at the end was this sentence: "On the route from the HIAL-137 Galaxy to the Solar System, ten tiny 'space-time disturbance points' traveling at five times the speed of light are about to appear. They are wrapped in a negative gravitational lensing field and cannot be observed by conventional means."

Professor Liu stood up abruptly; because the movement was too fast, his chair was knocked over to the ground, making a loud noise.

He paid no heed to this, rushed to the desk, and picked up his mobile phone.

His hand was shaking violently; he tried several times before he finally dialed the number he knew by heart, which belonged to the head of the Project Starlight Seeker project team, who was also a member of the Standing Committee of the State Council.

The phone rang only once before it was answered.

"It's me, Old Liu." His voice had become hoarse due to excitement.

"I have received a letter!"