Upon detecting that foreign material had entered the star system, Xiao Yu reacted immediately.

He piloted a Village-Class ship, quickly approaching the incoming meteorite.

Material analysis showed that the meteorite was composed mainly of iron, with some traces of dry ice and ethane mixed in. Its size was only about 10 meters by 6 meters by 3 meters, with a mass of just a few thousand tons.

The nearest stellar body to this star was still hundreds of light-years away. At the edge of the Milky Way, matter was extremely sparse. This meteorite might have formed within a nascent star system inside the galaxy and then, due to gravitational interactions, been flung out. After tens of millions or even hundreds of millions of years of drifting, it had arrived here and happened to be captured by this star’s gravity.

The meteorite was completely ordinary, something you might see in any young star system. However, its appearance here carried unusual implications.

First, one thing was proven: the gravitational pull of this star had not been blocked. In other words, the star could still attract objects from outside the barrier.

Of course, it was also possible that the gravitational pull had been blocked and that the meteorite’s arrival was pure coincidence. But the probability of that was incredibly low. Without gravity, for this meteorite to just happen to enter the influence range of the star was as unlikely as shooting a mosquito from a light-year away with a handgun.

That possibility could be safely dismissed.

This phenomenon triggered some concerns for Xiao Yu.

To guard against unexpected situations, such as the meteorite potentially having some special structure, Xiao Yu marked the meteorite and then tried to push it out of the star system.

The result: when the meteorite came into contact with the red barrier, it disappeared suddenly, just like the Village-Class ships that had been used for earlier experiments.

However, communication remained intact. Xiao Yu had installed a communication device on the meteorite.

Xiao Yu instructed the radio broadcasting equipment, which had been pre-installed on the meteorite, to send out a broadcast. Then, with a mixture of complex emotions, he watched as the satellites positioned throughout the star system received the signal.

This confirmed that the meteorite had not left the star system. It had simply been teleported to the interior, just like the Village-Class ships.

“Inbound only, no outbound…” Xiao Yu sighed internally. “This barrier seems to allow external material to enter but prevents anything from leaving. If that’s really the case…”

“If it really is inbound-only, then I should still be able to see the starlight from outside. There’s no reason that a meteorite can get in but external starlight can’t.”

Thinking along these lines, Xiao Yu redirected various optical observation instruments toward the barrier.

He aimed the array telescope at what he estimated to be the location of the galactic center, the brightest spot.

The array telescope captured a high-resolution image. In this image, Xiao Yu performed extensive processing: extinction correction, noise reduction, and other methods one after another. In the end, he obtained a blurry photo.

After filtering out the glow of the red barrier, Xiao Yu could faintly make out a blurry bright spot in the center of the image.

That bright spot was, without a doubt, the galactic center, the core of the Milky Way.

“Just as I thought. I’m not actually cut off from the outside world. External matter, and even light, can still enter this star system. The reason I couldn’t observe starlight before was because the glow of the barrier was too overpowering,” Xiao Yu concluded, though he also felt a bit unsettled.

“Inbound-only… this characteristic feels eerily similar to a black hole. If there were an external observer, and they noticed that light entering this region could not escape again, while still detecting gravitational pull here, would they mistake this place for a black hole and assume the barrier marks the event horizon of such a black hole?”

The event horizon is the gravitational boundary of a black hole. At the event horizon, the escape velocity is exactly the speed of light. Since light speed is the upper limit of physical motion, light can still escape from outside the event horizon, but once it crosses into the event horizon, the escape velocity exceeds the speed of light, and light can no longer get out.

To put it simply, the event horizon is the edge of a black hole. Before reaching it, there is still a chance to escape; after crossing it, you’re doomed, never able to get out again.

“But this place clearly doesn’t match the characteristics of a black hole. For instance, when approaching the four-dimensional barrier, matter isn’t torn apart by gravitational forces. If there were an external observer, they should be able to easily tell that this is not a black hole.”

“In any case, I still can’t be certain whether I really have the ‘absolute safety’ that Taihao claimed. Danger still looms ahead. Leaving here as soon as possible is the only true path,” Xiao Yu thought.

“Hmm? Inbound-only, inbound-only…” Xiao Yu silently repeated the phrase to himself, when suddenly a spark of inspiration hit him.

“Taihao said that if I can break through this barrier, I will be able to master four-dimensional space shield technology. So… that’s what a four-dimensional shield is all about.” In that moment, Xiao Yu felt a flash of clarity.

“This four-dimensional barrier allows matter to enter but not leave from the inside. So obviously, for the outside world, it would have the opposite property, it allows things to exit but not enter. If I can make use of that, and install a layer of such a four-dimensional barrier around a spaceship, wouldn’t that be perfect?”

“First of all, the spaceship’s own attacks, thanks to the ‘exit-only’ principle, would easily penetrate the four-dimensional shield and hit external targets. Meanwhile, attacks from enemy ships, whether they are light-based attacks or physical strikes would be blocked from entering, meaning my own ship would remain completely protected. This… this kind of technology would be incredibly powerful. If I can master it, wouldn’t I be invincible, with no force able to damage my ship?”

Thinking of this, Xiao Yu grew excited.

“I never expected that the gift Taihao gave me would turn out to be so valuable. Hmm, this gift is truly invaluable. To show my gratitude, I’ve decided that when my technology becomes advanced enough, I will fulfill your final wish and travel to the Large Magellanic Cloud to complete your last request.”

Xiao Yu made a silent vow.

Taihao’s dying wish wasn’t simple, but it wasn’t impossible either.

Just as Xiao Yu was starting to feel exhilarated, two new considerations quickly came to mind, and his excitement calmed down right away.

“First, even Taihao itself, which was already a half-four-dimensional entity, was shattered by the Sweepers’ Neutron War Star, causing its death. This indirectly proves that the four-dimensional shield is not omnipotent. It must have some kind of limitation. The most likely scenario is that it has an energy threshold, meaning that after mastering four-dimensional shield technology, my ship could be immune to all attacks below a certain level, but if an attack exceeds that limit, the four-dimensional shield can still be destroyed.”

“Second, the exit-only property would mean that my ship wouldn’t be able to receive any external information. Obviously, if attacks can’t get in, external data won’t be able to get in either. This would make it impossible for my ship to communicate via radio waves, impossible to position itself using neutron star navigation systems, and impossible to detect enemy ships. In simple terms, anything outside would be completely invisible to me because internal light can exit, they can clearly see my position, but because external light can’t enter, I wouldn’t be able to see them. Hmm… communications can be resolved using superluminal communication technology, and as for intelligence gathering, I’d have to rely on deploying a large number of satellites.”

Xiao Yu quickly thought through the pros and cons of the four-dimensional shield and began to sketch out initial battle strategies for when he eventually mastered this technology.

To summarize, after acquiring the four-dimensional shield, Xiao Yu’s battle strategy would work like this: deploy a large number of satellites without shields to serve as scouts and gather all the necessary intelligence on the enemy, such as ship positions, movement directions, attack trajectories, size, mass, firepower, and so on. Then, using superluminal communication, all that data would be sent to the flagship protected by the four-dimensional shield. The flagship would process this information and, through superluminal channels, direct the rest of the fleet in combat.

Because of the four-dimensional shield, Xiao Yu would have to completely separate intelligence gathering and combat into two independent components.

This was a drawback, but clearly, compared to the benefits, the downside was negligible.

“I wonder what level of technological advancement I’ll need to achieve before I can break free of this prison and master four-dimensional shield technology,” Xiao Yu mused. “It’s probably tied to Faster-than-Light Travel technology. Faster-than-Light Travel involves warping three-dimensional space. I wonder if warping three-dimensional space would affect four-dimensional space… no point worrying about it now. Once I’ve developed Faster-than-Light Travel, I’ll run an experiment to find out.”

Resolving himself, Xiao Yu dove back into endless rounds of experiments and data processing aboard the Hebei.

The Luka people could relax and celebrate, but Xiao Yu could not. And even if he wanted to have some fun and relax, there really weren’t any entertainment activities for him to do. After all, no matter what the entertainment, to Xiao Yu, it was all just a tangle of data. Frankly, it was quite dull.