It was ‘down, down, and down’ again, Marisol’s gravity harness dragging her to the walls of the whirlpool as she pinched her nose and quickly huffed out a blubbering of bubbles—by the time she landed, glaives stabbing into the ground of pale stone, her body had already acclimated to the pressure at the edge of Depth Two.
Because there was nothing on the surface of Depth Three.
Is this it?
Depth Three?
Squinting, staying on one knee, she surveyed the thousand-metre stretch in front of her and looked as far as she could see. The Tropical Reef of Depth Two behind her was as vibrant and teeming with life as ever, and Depth Four, in the far, blurry distance, appeared to be a land of canyons with mountains of stone jutting out from the ground, but… between the two, Depth Three was nothing but an empty, barren plain of rocks, a few dead corals, and a few wilting shrubs swaying in the gentle undercurrents.
It wasn’t just the stretch of Depth Three in front of her that was barren. Looking up and around the circular walls of the whirlpool, Depth Three was just an entire ring of nothing. It was as if someone had plucked out all the giant corals and weeds and shells from the Tropical Reef and didn’t bother reseeding the land for future harvests.
Quite frankly, she was disappointed at how boring Depth Three looked—and that was, until Reina and the Imperator siblings trudged past her, tapping her on the shoulder and telling her to look down at her feet.
…
Holes.
Lots of holes.
Scattered across the barren surface, faintly glowing cave entrances dotted the land like strange, bioluminescent honeycombs, and Marisol took a sliding step backwards out of caution. Each one seemed to breathe faintly, underwater currents pushing in and pulling out of the caves as if they were alive. Definitely unsettling, but intriguing all the same.
Curious, she followed after the Imperators and peered down the closest hole they were gathered around. The phosphorescent bluish-pinkish light came from glowing crystals embedded in the vast cavern walls. The cave itself wasn’t particularly narrow or cramped, either—there was enough space for everyone to move around comfortably, so she didn’t feel claustrophobic just looking down at it.
As for how deep, how long, and where the cave connected to… she had no idea. The bottom of the cave was fifty metres below, but she could tell the walls opened up down there, so there was probably an entire web of caverns just below the surface.
“... Welcome to Depth Three, the Crystal Kelp Caverns,” Helena said, glancing at her as the Imperators each whipped their hands up, catching silk threads flying at their heads without even looking. Marisol caught hers instinctively as well, but it wasn’t until she turned, looked up, and saw Hugo waving down at them from the side of the diving bell that she realised it belonged to him. “You just stick Hugo’s thread onto the back of your harness. It won’t snap unless something really powerful comes in contact with it, so he’ll be able to yank us out from the winding caverns if we need to abort the mission at the drop of a hat.”
Seeing everyone just slap the ends of their threads onto their backs, Marisol did the same, giving it a good few pats just to make sure it was secure. “I thought… well, I thought Depth Three was just like another Tropical Reef. You’re telling me we have to fight down in these holes?”
“The Crystal Kelp Caverns may be buried beneath the walls of the whirlpool, but they are no less a ‘Depth’ that the Imperators must regularly patrol and keep tabs on,” Reina said curtly, fixing her braid into a bun as she did. “I will remind you all that the allotted mission duration is two hours. I will attempt to follow its pheromone trail based on the extract the scouts let me smell prior to the mission, but whether we find and slay the Mutant or not, we will not be staying within the caverns for any longer than that. Is that understood?”
The Imperator siblings saluted with a loud ‘clear!’ and stepped up to the edge of the hole, rubbing the shell on their pistol shrimp claws. Reina stepped up as well, giving Marisol a plain nod before walking off the edge—and the siblings followed without hesitation, their silk threads following them down the cave.
For her part, Marisol turned back and looked up at Hugo again, watching him extend the threads continuously by pulling more silk from out between his gritted teeth.
‘Go along, now’ seemed to be what he was telling her with his slanted, amused spider eyes.
…
She wasn’t exactly sure what had her so worried about the whole mission, but she couldn’t very well lag behind now.
Taking the plunge, she let her gravity harness drag her even further down, and she made sure not to fall past and scrape herself on the sharp, glowing crystals. Fifty metres was a long way down, but she managed to land safely on two glaives, kicking up a small poof of sand and silt as she did.
Reina and the Imperator siblings were already waiting for her, and without another word, they began heading down one of the caverns leading away from the overhead chute.
So this is Sector Sixteen of the Crystal Kelp Caverns, huh?
[Correct.]
How many sectors are there in Depth Three?
[Three hundred and sixty across the entire Depth,] the Archive answered. [For your reference, each sector simply refers to the ‘degree’ of the perfectly circular walls of the whirlpool. There are three hundred and sixty degrees in a circle, so Sector Sixteen of any Depth just means it is located sixteen degrees going clockwise, with Lighthouse Seven serving as the sun-facing zeroth degree.]
The narrative has been taken without authorization; if you see it on Amazon, report the incident.
Huh?
[... Did you not say you went to school?]
For a while. I aced all my tests back then, but I dropped out early so I could work.
The Archive sighed, and she resisted the urge to flick it off her shoulder. [Then the explanation is meaningless. Just know that these caverns spread out across the entirety of Depth Three, so please do not separate from the Imperators. If your thread is severed and you lose yourself down here, even I am not confident I can guide you back to the surface.]
Marisol could definitely see why. Past the glowing kelp stalks, the phosphorescent crystals jutting out the walls, and the vibrant anemones dotting the ground in grassy, mossy chunks, there were dozens and hundreds of forks she could easily hurtle herself down—and she could already see a thousand different things that could kill her without her even knowing they were dangerous. Thin, ghostly eels weaved between their feet. Clusters of tiny shrimp-like critters scuttled around the cracks and crevices of the walls. Some flowers were star-shaped with petals that curled back like meat hooks, and a few anemones released faint mist when she stepped on them, creating faint halos of light around each bloom.
She’d definitely kill herself if she got lost down here.
“The Crystal Kelp Caverns are still considered ‘safe’ by the Imperators’ standards,” Helena said, throwing a glance back at her as she kept looking around, studying the mineralised flora with widened eyes. “Commercial diving companies are allowed to dive down here and harvest the local resources, and these caverns, in particular, are especially important to powering most of the city’s infrastructure.” Then Helene tilted her head at one of the glowing bluish-pinkish crystal chunks, ripping a small piece off with her claw as they walked by. “You’ve seen one of these around the city, right?”
Marisol blinked back in response before focusing on her throat, making the Hydrofuge Spines around her lips vibrate as she mouthed her words.
“Uh… no,” she mumbled, and Sonar Translation made her voice come out almost perfectly clear; her words still warbled and slurred a little, but she’d get better at talking underwater eventually. “I… haven’t really gone out into the city the past month. Are these crystals supposed to be common or something?”
Aidan and Bruno looked back at her strangely. “Seriously?” Aidan exclaimed. “The street lamps, mechanised warships, and countless other machines in the city all use Encrystals as their power source,” Bruno said steadily, plucking another small chunk off the wall as they turned right down a crossroads. “Though, I’m not surprised you don’t know about them. Realistically, they can only function as a light-based power source in the Deepwater Legion Front. They lose their innate heat and glow if they’re away from the deep blue for too long, so they’re unwieldy to transport and store anywhere else on the continent.”
“Really?”
Thinking back on it, she’d never actually thought about how the city’s lamps and lanterns were kept perpetually lit even without people performing maintenance every few hours or so. There was a reason why nights were dark in the Luzde Oasis Town where she came from—it was just too much of a hassle to have someone feed the braziers all-night long.
“So… the ‘Encrystals’ don’t gotta be replaced ever?” she asked, looking at the crystals with newfound light in her eyes. “That ain’t bad at all. My mama would love something like that–”
“They glow forever as long as they’re in the Deepwater Legion Front,” Bruno explained. “They’ve been growing in the Kelp Crystal Caverns for several decades now, but we believe the Encrystals are by-products created by Corpsetaker's Swarmblood Aura, so they glow only when they're close to him."
Marisol tugged at the glowing crystal on her chest, pulling on the straps of her harness. “And these gravity harnesses are powered by Encrystals as well?”
“No. These ones are slightly different. The gravity-controlling crystals are forged with a bunch of different leviathan parts, but the most important part would have to be Venossa’s scales—a Lesser Insect God damselfly that used to live near the city, in the Dead Island Straits. The scales on its wings have low-gravity properties.”
The Archive poked her cheek as though trying to jog her memory, but she remembered that archipelago too dearly. This ‘Venossa’ was the one you said the Worm God and the Thousand-Tongue killed, right? It was killed so violently its parts were scattered across the great blue?
[Correct.]
“You guys are really good at making stuff out of bug parts, then,” she mumbled. “But if Corpsetaker dies, the Encrystals ain’t gonna function anymore, right? Because it ain’t gonna release its Aura anymore, and then–”
“Well, yes,” Bruno said pointedly. “But if Corpsetaker dies, there is no more reason for the Whirlpool City to exist.”
Marisol’s lips thinned into a line as they travelled deeper and deeper into the caverns, her face a little forlorn.
The thought that the entire city was built just to contain a single bug—a Greater Insect God—was both frightening and saddening.
So the entire city will just crumble on itself the moment Corpsetaker is defeated?
[Correct.]
Everything they’ve built here—the lighthouses, the upper city, the lower city, the diving companies, the harbours, the warships—will just cease to function the moment the Greater Insect God is killed?
[Correct.]
The decades of research and cataloguing every single Depth of the whirlpool will just become completely useless?
[If Corpsetaker is slain, the Deepwater Legion Front wins,] the Archive murmured. [It is the same for the other Swarmsteel Fronts. Not a single Greater Insect God has fallen in nearly an entire century. If Corpsetaker is slain, I am sure everyone in the Whirlpool City would be more than happy to return ashore—that is where their ancestors came from, after all.]
…
Suddenly, her task of having to reach Depth Nine so the Archive can ‘analyse’ what Corpsetaker and his Four Lesser Leviathans were planning didn’t sound so easy anymore.
But, before she could even think about the Greater Insect God who resided at the very bottom of the abyss, she had to deal with the Mutant in front of her first—and she knew, the second all five of them stepped foot into a vast cavern where glowing crystals were the ground, walls, and ceiling, that it was a Mutant behind the coordinated copepod attack a month ago.
A scowl twisted Reina’s face as she flicked her scorpion tail out to the side, stopping the rest of them from walking any further. The cavern may be incredibly spacious with lots of room for them to scatter wherever which way, but the fact was, the Mutant with four arms, two legs, and half-transparent orange chitin was curled up in a completely defensive little ball in the centre of the cavern. It was facing away from them. It didn’t even seem like it’d noticed them intruding upon its abode.
Marisol couldn’t help but clench her jaw and shiver in the face of another Mutant-Class. Its Swarmblood Aura was scentless, but it was thick, heavy, and powerful, every bit like the Mutant skeleton shrimp she'd fought before.
Apparently, the Imperators were trained not to feel such fear.
When Reina snapped her fingers almost casually, the Imperator siblings pressed their pistol shrimp claws together and clicked at once, sending a resonating wave towards the Mutant. The wave tore a straight line through the small crystals on the ground, but without even looking, the Mutant whipped an arm back and made a clawing motion.
Half a second later, a swarm of tiny copepods burst from the ground like a living root, moving in the exact same direction as its claws to intercept the sound wave.
Then, and only then, did the Mutant snap its own neck to crane its head backwards—two bulbous white eyes boring holes into Marisol’s face.
“... Time: Ten fifty-two in the morning, First Day Crab, Month Firefly,” Reina said plainly, the Imperator siblings fanning out to her sides as she reared her scorpion tail behind her like a blade. “C-rank Mutant-Class copepod location confirmed and encountered in Sector Sixteen, Depth Three. Commencing immediate and aggressive extermination. I do not want more paperwork from rescheduling another mission.”