Crossover Shipgirls: Building a Dimensional Empire from Scratch

The Human United Fleet could not comprehend what had just happened.

The space navy was far too reliant on so-called advanced technology.

On every starship’s radar display, there was no sign of the massive warship’s movement.

Technically, it was invisible to everyone.

Logically, a starship the size of the Moon should have caused obvious disturbances to other planets in the star system.

Yet it had no gravity at all—neither gravitational wave detectors nor radar could detect even the slightest anomaly.

Only when it was close enough could one see the giant with the naked eye.

In fact, people on Earth watching the spectacle saw the Eternal Snowfall before the United Fleet’s crew did.

Looking up at the night sky…

On one side of the night hung two thousand points of light—the space navy fleet.

On the other, like a meteor the size of the Moon streaking across the heavens.

As it passed perihelion, the massive wings blotted out the moonlight and stars, casting a huge shadow over the Northern Hemisphere.

Nearly all of Eurasia was engulfed in the Eternal Snowfall’s shadow.

Earth’s people stared dumbly at the sky.

No space navy intelligence had ever mentioned a planet-sized warship.

The Trisolaran First Fleet was still two centuries away from reaching Earth.

At present, only a probe had arrived.

As for other aliens?

Humanity remembered no other extraterrestrial civilizations beyond Alpha Centauri.

And a ship of this size approaching from deep space—there was no reason the space navy wouldn’t have detected it.

”Run? Run where? Why?”

”Where did it come from? Why didn’t we detect it?”

The officers beside Ding Yi blurted out the questions instinctively.

After discovering the Eternal Snowfall, most fleet captains and crew, along with the United Fleet’s supreme commander, were briefly stunned into silence by the shock.

”No anomalies from gravitational wave or radar scans?!”

Ding Yi had wanted to urge the fleet to distance itself from the giant warship, but soon an even more shocking report came from a technical officer.

”Nothing. The detection stations in Saturn’s orbit haven’t seen a thing.”

The officer shook his head.

Ding Yi frowned, thinking for a moment.

Cold sweat began to bead on his forehead.

A planet-sized ship entering the Solar System completely undetected meant, in his understanding, two possibilities:

One: its counter-detection technology surpassed all human capabilities—gravitational waves, electromagnetic waves, nothing worked on it.

Two: during acceleration, it exceeded the speed of gravitational wave detection—that is, faster than light.

Electromagnetic waves from detectors couldn’t keep up with its speed, no signal could return, and thus no human—or any civilization in this universe—could detect it with observation instruments.

It could be the first, the second, or both.

Ding Yi shook his head—he found the second possibility too terrifying to believe willingly.

”Asia Fleet, North America Fleet, Europe Fleet, disperse! Enter combat readiness!”

The space navy’s commander quickly issued the order.

The three fleets, over two thousand starships, slowly adjusted formation.

With their basic science locked, humanity could build spacecraft, but an effective command system had yet to be established.

For a moment, chaos rippled through the starship group.

A thousand kilometers away, the Droplet seemed to sense something.

It turned toward the Eternal Snowfall, emitting an invisible gravitational wave in an attempt to probe the giant warship’s internal structure.

But the ship’s built-in tachyon interference rendered it futile—the returning signal was nothing but garbled data.

In the realm of electronic warfare, sub-light natives could never compare to an FTL civilization.

Their foundational sciences were on entirely different levels.

Aside from using the naked eye, any technological attempt to spy on the Eternal Snowfall was futile.

”Tsk, tsk, tsk… this feels like ancient cavalry trying to disrupt an aircraft’s radar by shouting loudly,” Nymph quipped from the bridge.

Vmmm—

The Droplet reacted far faster than the human fleet.

Realizing all detection methods were useless, a blue halo formed at the tip of its tail, rapidly expanding, shifting from blue to yellow, and finally to red.

With the halo’s propulsion, it accelerated sharply—moving at ten times the third cosmic velocity, piercing through the nearest two human ships, then making an acute turn in defiance of both momentum and angular momentum conservation laws.

It fled at maximum speed in the opposite direction of the Solar System.

The Trisolarans’ technology far surpassed Earth’s; as a civilization that entered the space age earlier, they regarded Earth’s fleet as insects.

Earth’s insects could not understand Trisolaran technology.

Yet the Trisolarans also couldn’t comprehend the giant starship blotting out the stars before them.

Which meant, in the other’s eyes—they too were insects.

”Hide yourself.”

This was a truth the Trisolarans had learned long ago.

They understood perfectly how terrifying a technological gap could be in space warfare, and had no intention of tangling with the Eternal Snowfall.

They didn’t even bother with the human Solar System fleet, though the Droplet could have annihilated them in thirty minutes.

Instead, it simply turned and ran.

”You’re not getting away~”

On the bridge, massive holographic interfaces appeared before Nymph.

Her eyes turned red, data streams flowing across her pupils as her fingers danced rapidly over the displays, locking on to the Droplet’s position.

The universal electronic warfare Angeloid had also undergone upgrades after acquiring FTL tech.

Though her combat power was no match for Ikaros or Astraea, Nymph possessed the strongest information and electronic warfare capabilities in the entire base.

Vmmm—

The Droplet suddenly halted in space.

It was as if both sides were struggling for control.

Then it began to emit a dark red glow, attempting to trigger its self-destruct.

”What? Can’t win so you’re flipping the table?”

The blue-haired loli pouted, tapped a few more commands.

Minutes later, the glow faded, and the Droplet stabilized in space.

”All done, Commander! It’s paralyzed, and I’ve disabled its self-destruct!”

”Bring it back and we can modify it for our own use~”

Nymph tilted her head up proudly toward Setsuna.

”Good job.”

Setsuna patted the little Angeloid’s head.

After the hatch opened, two Angeloids piloted a small shuttle to retrieve the Droplet.

”It’s beautiful—like the Virgin’s tear.”

Kayo Senju made a face and prepared to dismantle it for study.

She’d worked hard to convince the Commander to let her join this expedition to the Trisolaran world.

”Hey???”

”Are you all addicted to cosplay or something?!”

...

On the other side of the Solar System—

The Natural Selection fled at 1% of light speed.

In the Proceed to Four state, all crew were already in hibernation.

Zhang Beihai locked himself inside a spherical cabin, speaking to Dongfang Yanxu through the internal comms.

”The pursuing fleet is only 1.2 million kilometers from the Natural Selection,” Dongfang reported.

”Your pessimism about the war is unfounded. Now, the Trisolaran world has shown signs of negotiation, the Solar System United Fleet has already set out to intercept their probe—the war is about to end in humanity’s victory.”

She tried to persuade Zhang Beihai to abandon his escape.

”I saw the news…”

Zhang shook his head.

The Natural Selection was still in contact with Earth, but as the ship moved farther from the Solar System, delays in receiving news grew.

”You still insist on your defeatism and escape plan?”

”Yes. I believe humanity will lose.”

Zhang sighed.

”...”

Dongfang wanted to say more.

She searched through the latest news for something about the United Fleet to convince him to give up.

Then, one explosive headline made her freeze.

The young captain double-checked it many times—it wasn’t a joke from Earth.

Finally, with some hesitation, she said:

”...Something’s happened.”

”A strange ship appeared in the Solar System not long ago. The Droplet was taken—by aliens.”

”...”

Zhang Beihai: ”?”

...

Solar System, beyond Neptune’s orbit.

The Human United Fleet stared, stunned, at the massive warship that had suddenly appeared.

It hovered tens of thousands of kilometers away, and simply looking at its colossal hull exuded a crushing sense of pressure.

Meanwhile, Earth’s news outlets were broadcasting live coverage of the battlefield anomaly.

”The Solar System United Fleet has detected an unidentified alien warship beyond the outer orbit!”

”Based on estimates, this vessel is comparable in size to the Moon, and it appears to have captured and restrained the Droplet through some form of technology!”

”This is not part of the Trisolaran fleet. The Human United Fleet is now in a standoff with the alien craft.”

”No matter what enemy appears, the space navy will loyally defend the Solar System…”

From Saturn Base’s feed, viewers saw the United Fleet shifting into a dispersed formation.

Part of the fleet moved to face the target head-on, while others fired up engines to flank the Eternal Snowfall.

Spectators on Earth became animated, though some wore worried expressions.

”Tsk, tsk, tsk… I knew just one Droplet would be boring—finally a real big one shows up!”

”Is this a Trisolaran ship? Doesn’t look like it…”

”This thing should be enough for the fleet to fight, right? I mean, it’s big enough.”

”What’s the point of size? In space, it’s just a big target! Can it survive concentrated fire from two thousand stellar-class ships?!”

”Hey, can we get the aliens to give us back the Droplet? That should be the United Fleet’s spoils, right?!”

”….”

All this chatter reached the Eternal Snowfall, making Setsuna and the shipgirls chuckle.

Humanity’s inflated confidence was at an all-time high.

They truly believed they could handle the Droplet and the Trisolaran First Fleet with ease, dismissing any foe.

If the Resetters showed up, they’d probably want to slap them, too.

Before long, a communication request pinged the Eternal Snowfall’s AI.

”Hello? Where are you from?”

”Hello?”

”%*@?”

The United Fleet sent greetings in dozens of languages, complete with a translation array marked with mathematical symbols for each character set.

In space, math was universal—numbers and mathematical laws could be used to translate into any language.

”What age is this? You don’t have AI with auto-translation systems?”

Setsuna tossed the translation data aside.

Clearing his throat, he gave a signal.

The Eternal Snowfall’s sensors instantly linked to all 2,015 stellar-class warships, as well as the human space navy’s Jupiter Base and the United Earth Government.

Even the fleeing Natural Selection, Blue Space, Ultimate Law, and others received Setsuna’s transmission.

Shwoom—

A holographic display opened aboard every ship and before every government and military official.

Zhang Beihai, still mulling over Dongfang Yanxu’s shocking news about aliens, was startled when an unfamiliar man appeared on the main console.

Setsuna addressed them all.

”They just cracked all of humanity’s communications networks instantly?”

Ding Yi, Zhang Beihai, and others were briefly stunned.

This was a military-encrypted network—no one should have been able to tap in so casually.

”Humans of the Solar System, greetings.”

”We come from another world—you may call us the Starsea Empire.”

Setsuna kept his self-introduction short and direct.

”?”

”He’s human?”

The top commanders of the United Earth Government and the space navy stared hard at the hologram of Setsuna.

They scrutinized him repeatedly.

No matter how they looked at him, he was indistinguishable from an Earth human.

And he was a Common Era human.

After two to three centuries of development, the Trisolaran world’s mainstream aesthetics favored androgynous, soft beauty.

Setsuna’s demeanor resembled that of Common Era soldiers who had gone into hibernation centuries ago under the Reinforcement Plan—people like Zhang Beihai or Chu Yan.

Hiss—

On Earth, the live news audience erupted.

”Human?! The alien is human?!”

”Could he be some kind of shapeshifter that can turn into anything?!”

”Or a species that changes form to match whoever it meets—human before humans, Trisolaran before Trisolarans?!”

”….”

After some deliberation, the United Nations and the space navy’s commanders let the United Fleet’s supreme commander speak first.

”Your civilization is called the Starsea Empire? Could you explain further? You appear to be the same species as us—what star system are you from?”

”I’m also from the Solar System—just from another universe’s Solar System. You should understand what I mean.”

”Parallel universe?!”

The concept was common in Earth literature, and humanity quickly reached a rough consensus.

Cheers rose at the discovery of a new civilization.

”!!!”

Only aboard the Quantum and the Natural Selection did Ding Yi and Zhang Beihai’s expressions grow heavier.

”Can the Quantum enter deep-sea state, ready to proceed to Four at any time?” Ding Yi asked.

”Why?” the technical officer asked, puzzled.

”That ship… it gives me a very bad feeling…”

Ding Yi tapped his pipe on the table.

”A starship that can cross worlds… it’s not something simple. It may be more dangerous than the Trisolaran civilization…”

He wanted to explain that the Eternal Snowfall wasn’t just thousands of times larger than the human fleet—it was something far beyond.

Light speed, world-crossing…

A terrifying picture formed in his mind, though his knowledge wasn’t enough to grasp it fully.

But the crew dismissed his concern.

”Trisolarans? Ding, they’re no threat anymore.”

”If that random alien hadn’t interfered, the Droplet would’ve been ours.”

”The Trisolaran First Fleet is probably turning tail right now, hahaha…”

”….”

After the chatter, attention returned to Setsuna.

They were endlessly curious about the massive ship from another world.

”Then, may I ask your purpose here in the Solar System, Mr. Lu?”

The fleet commander spoke.

”On behalf of humanity, I welcome you. We can establish cooperation between our worlds—our scientists are very interested in your civilization.”

”We can exchange and share advanced technologies…”

He painted grand visions—mutual immigration, visiting the Starsea Empire’s Solar System, shared technology, and more.

The people of Earth quickly lost themselves in dreams of tourism to another universe.

”….”

Setsuna thought he might have arrived at humanity’s most retarded period.

He coughed, cutting through the officials’ fantasies.

”Unfortunately, I have no such intention.”

”The Solar System will be incorporated into the Starsea Empire as a forward research station.”

”And you… after disarming entirely, will be allowed to live on Earth at pre-space-age standards.”

”In the future, you’ll live alongside other aliens. I will ensure your basic living conditions, but abandon unrealistic delusions.”

”Forget your so-called freedom, art, and other nonsense. The universe is cruel.”

Before departure, Setsuna had considered how to handle the Trisolaran world’s Earth and its humans.

These troublemakers were unfit as vassals, and resource exploitation in such a chaotic universe might not be worth the investment.

The Solar System was already nearly stripped bare.

He decided the best option was to build a small stellar base here for research.

The Trisolaran world held many interesting things, but you couldn’t take them all in one trip.

High-risk projects like dual-vector foil experiments weren’t safe in his own universe—but here, they were ideal.

In the future, perhaps even ether engine experiments could be run here—failures wouldn’t matter.

And it would be a good opportunity to study aliens like the Singers and Trisolarans.

”???”

”Accept Starsea Empire rule? Disarm?!”

The UN officials and fleet commanders were stunned.

”Yes. You have thirty minutes to decide. The United Fleet is to surrender, and the Solar System will come under Starsea Empire administration.”

”As for the Trisolarans…”

Setsuna glanced toward Earth, knowing sophons were listening.

”I will allow no more than fifty thousand Trisolaran survivors, relocated to Australia on a reserve, living at low-tech, pre-space-age standards.”

”We have some interest in researching aliens.”

”Likewise, all your ships will be destroyed. You will never enter space again, nor conduct any research work.”

Clack—

He slapped the table, stood, and let his voice echo through the silent Earth and space fleet.

”This is the final offer. There is no room for negotiation.”

…

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