After paying respect to the fallen soldiers, Michael arrived at the rooftop of an apartment building, the sky having already turned dark. He dropped his backpack near a railing and took out a small booklet that he had looted from the group of soldiers earlier, and took a seat at the edge of the rooftop.
The booklet appears to be a basic guide titled 'New Eridu 101: Hollows, Ether, and Ethereals.' The inclusion of the word 'New' in 'New Eridu' suggests that there was an old Eridu, and it is not difficult to guess what may have happened to it. Nevertheless, and to distract his mind from his previous encounter, Michael opened the booklet and started reading the first section.
"Hollows. Appearing out of thin air and with little to no warning, and swallowing everything in their paths, they are characterized by their spherical appearances, which are black in colour." It then showed a picture of what is called Hollow Zero, taken from a military camp called Scott Outpost.
Michael couldn't help but whistle when he saw the size of it. At first, he had thought the camp was close by, but when he saw what he thought was dust but was actually a helicopter in the distance, he truly began to realize the sheer size of it.
"The interior inside of a Hollow is nothing short of a distorted maze where normal laws and physics don't apply." Michael looked around at his surroundings and couldn't help but jokingly comment about it. "You don't say."
The booklet then went on to basically describe how screwed you were if you ever got stuck inside a Hollow with no way to navigate it. What may seem a way out is in fact a dead end, and vice versa, a fissure that could either teleport you to a different part of a Hollow, into another Hollow entirely, or just teleport you to the sky, with no parachute. Not only that, but the Hollows also frequently shift, making any attempt to map them out futile. If that wasn't bad enough, communication inside and outside of Hollows is nearly impossible or heavily delayed.
This is why the booklet stresses the importance of having a navigation Bangboo equipped with Carrot Data, a program that can map out a Hollow by predicting its behavior, to safely navigate the Hollow. Attached at the end of the line is a picture of the Bangboo in question. A rabbit-like robot that he had seen before at the orphanage's photo.
"So that's a Bangboo. The one at the orphanage must have been made for a different purpose since their appearance are different. Pretty cute."
The booklet then off-handedly mentions a 'black wall' that surrounded New Eridu, and Michael finally understood that this wasn't a post-apocalypse world as he had originally guessed, but instead a post-post-apocalypse world, with the only thing standing between humanity's extinction at the hands of the Hollows being the city of New Eridu.
And even that is a fight that humanity is losing as he read how, should a Hollow expand due a rise in their activities, which could happen in a variety of ways, it may hit a 'Zenless Limit' and spawn Companion Hollows which could have a feedback loop of their Companion Hollows expanding and consuming its new surrounding before then hitting their own 'Zenless Limit' thus starting the cycle anew.
It then lists the Six Great Hollows of New Eridu, all of which have a shared parent of Hollow Zero. Cretan, Lemnian, Papago, Pursenas, Solove, and Hawara.
Thankfully, humanity had developed several ways to combat the Hollow and either stop them from expanding further or even shrink them, entirely eradicating them.
The first way listed was to simply go into a Hollow and kill Ethereals, as destroying a large number, or a particularly strong one, can shrink a Companion Hollow, and in some instances destroy it entirely.
Of course, this strategy only works on smaller Hollows, as the larger a Hollow is, the more numerous and stronger Ethereals you have to take down. In which case, a second method they use is utilizing something called a Shiyu Pillar, a massive structure that can extract Ether energy from a Hollow to purify and convert it into usable energy for the city.
This was also not without downsides, as any remaining Ether corruption had to be expelled regularly, forming Ethereals that had to be purged.
The illustration of a Shiyu Pillar showing the strange structure he noticed earlier, extending out of Hollow Zero, and extracting what he presumed was Etheric Matter with its top venting Ether corruption.
There was also the mining and refinement of Ether materials inside of Hollows, the most famous example listed was Porcelume Ore, an Ether-resistant material used in the creation of tools and weapons.
The third and last method to contain a Hollow is the most grim and destructive. Should an expanding Hollow be unable to be contained for any reason, the city can authorise the detonation of Shiyu Pillars, their immense stored Ether powerful enough to destroy the Hollow outright or at least stop their expansion by depriving Hollows of any more matter.
It was not hard for Michael to guess that this method was used as a last resort when a situation is truly and utterly FUBAR.
In fact, the booklet provided an example of when this method was used during an event called Fall of the Old Capital nine years ago, when Hollow Zero began expanding rapidly for unknown reasons.
Fourteen Shiyu Pillars were detonated during that cataclysmic event, their combined explosion powerful enough to cause a geologic chain reaction, which created what is now known as the Chasm, a massive, lifeless, and empty ravine that left behind nothing for Hollow Zero to consume.
To illustrate the devastating impact of the explosion, an aerial photo of the Chasm was displayed.
Michael paused his reading for a moment, his mind trying to comprehend how humanity managed to survive the Hollows, yet he couldn't help but feel proud that, despite all the odds stacked against them, humanity managed to hold on and even somewhat thrive in the face of an almost seemingly unstoppable calamity.
Still, stopping Hollow Zero came at a great cost as the booklet stated that all but a single division of the Eridu Defense Force, along with countless civilians, were killed in the disaster.
Turning the page, Michael then read the next section simply titled 'Ether'. "Ether. An energy that permeates everything in the world with many uses. So, kind of like radiation..."
It states that the most prominent use of Ether was, of course, power generation, with most buildings, vehicles, and appliances in New Eridu using it as an energy source.
Of course, it wasn't all sunshine and rainbows as the booklet then provided details of the negatives of Ether and on what would happen if one were exposed to a high amount of it, typically due to being trapped in a Hollow for extended periods.
Objects and structures degrade and become contaminated with Ether, while any life with little to no intelligence and sentience will rapidly be corrupted and turned into Ether.
Those with intelligence and sentience, however, have a fate far worse in store for them.
Humans and Thirens exposed to a high amount of Ether, no matter how high or low their Ether Aptitude was, will eventually undergo Ether Corruption, causing their bodies to develop Ether Crystals before mutating their heads into a Core before fully becoming an Ethereal, losing their mind and sanity in the process, stripping them of their humanity.
There is no way to reverse those who have been fully transformed into an Ethereal, and even those who escaped full transformation will be burdened with life-altering health problems.
The booklet recommended that only those with official training and high Ether Aptitude enter the Hollows. There are also Ether-resistant gear and equipment, along with anti-corruption serum, which, while they cannot fully protect an individual from Ether Corruption, can significantly slow it down.
Michael took note of the word 'Thiren'. 'Those must be what humans with animal traits are called.' He thought to himself.
Returning to the booklet, it mentions that machines and electronics, which were noted to be much more resistant to Corruption depending on their materials, were also not spared this fate.
Simple electronics and machines malfunction and can turn to various forms of Ether if left inside a Hollow long enough. Meanwhile, smart machinery with AIs and Intelligent Constructs can be corrupted and turn into an Ethereal, turning hostile against all non-corrupted.
Michael paused as he mulled over the mention of Intelligent Construct. He assumed it was referring to the mech, but considering it also separately mentions machinery, it must be something else. Too bad there is no photo of an Intelligence Construct.
Flipping over to the last page, the booklet transitions nicely to its last section titled 'Ethereals'.
"Ethereals. They are categorized into two groups. Ether Mutants and Corrupted."
Ether Mutants refer to Ethereals that naturally formed inside a Hollow and those fully corrupted by Ether. Corrupted, meanwhile, are those that have not fully succumbed to Ether Corruption and retain some of their old appearance.
Coming in all shapes, sizes, strengths, and abilities, the only common thing between them was the Core all Ethereals have, which subsequently was their weakspot. Although it noted that the strength of the Core varies, with weaker Ethereals being able to be killed with small arms fire while stronger Ethereals may require significantly more firepower, assuming their Cores are also unarmored. If they are, using armor-piercing rounds may be required to take one down.
All Ethereals, without exception, are hostile to all non-Ether life, lack emotions and intelligence, and only exhibit behaviour and instinct similar to that of an animal.
"That was rude..." Michael contemplates the last line of the section. If this guide is to be believed, then he should've lost his very humanity the moment he turned into an Ethereal; yet, for some unexplained reason, he still retains his memory and identity. Perhaps it was due to his unique circumstances? He had no idea.
Still, whatever the case may be, he will really need to be careful whenever he interacts with other people lest he be captured and studied by any would-be researcher. Not that he blames them or anything, he'd just rather not be tied down and dissected like a lab rat.
Turning the page, it presented three illustrations of Ethereals: Alpeca, Thanatos, and Doppelganger, along with their abilities. Alpeca can spew concentrated Ether at enemies, Thanatos has teleportation abilities, and Doppelganger can mimic living beings.
Michael took an interest in the Doppelganger's ability to shapeshift and mimic humans. Perhaps he can also do the same to himself?
"Calm down, Michael. You barely knew what Ether was a few moments ago. Baby steps."
The section concluded with it stating that Ethereals can't leave or survive outside the Hollows as their Cores will disintegrate the moment they do so.
"That's not gonna stop me from trying," Michael said out loud.
The last page of the booklet warns him of other dangers that can be encountered in the Hollow. Hollow Raiders, those who illegally trespass into Hollows, Proxies, those usually assisting Hollow Raiders, and Rebels, military personnel who had defected from NEDF for a variety of reasons, urging anyone to think twice before they ever think about being one of them.
Now finished, Michael closed the booklet and stored it in his backpack. While it's a bit of a shame that it has little information on New Eridu or what an Intelligent Construct was, but he supposed it couldn't be helped. This booklet was, after all, dedicated to the basics of Hollows.
And so, Michael sat on the edge of the rooftop for a while longer, his mind contemplating his next moves.
His first order of business, and the most important, was absolutely to find something to store his MP3 devices in. Considering it was the only thing that came with him in this new world, he'd rather not lose the only remaining connection to it.
The second is to find an exit out of the Hollow and find out if he could safely get out. If he can't exist outside of Hollows, then maybe he can learn a way to do so.
The third is to hopefully learn how to learn useful abilities that the Ethereals have. This one will, unfortunately, be filled with trial and error as he doubts anyone in New Eridu ever wrote a book on how to train Ethereals or even be interested in having a conversation with him without thinking he's just another Doppelganger.
The fourth is to find a Doppelganger and learns how it's able to shapeshift its form. While his blade is useful, he'd rather have both of his arms. That and to hopefully change his appearance so that he is not scary.
The fifth and final step is to find more information on New Eridu. This one is the least important, as if he couldn't leave the Hollow, the information will be pretty much useless. Still, it can't hurt to learn more. Maybe there's an electronic store with working phones somewhere in the Hollows.
With his five-step grand plan finalised, Michael got up from the rooftop and looked up to the night sky and towards the moon, where he made a discovery.
"Moon's haunted."