The descending undertrolley's iron hull shone with an amber glow. This was due in large part to an enormous light source looming far off the gondola's port side, just beyond a forested bank of rippling kelp.
As the cables carried the vessel further down, a series of bulbous spires emerged from the ocean's floor, converging around a glossy gold dome held together by incredibly thick iron bulwarks and rivets. The sprawling lengths of Shoggoth resembled several tiny campfires assembled tightly across a desert valley's floor.
The submerged lengths of the city stretched in every cardinal direction—much further than Rainbow had anticipated. It took a long time of gazing out the porthole, but she eventually surmised that only a small fraction of the city was inhabitable by surface dwellers such as herself. The very center of the urban sprawl consisted of several high-rising structures with yellow-capped summits. Even from a long distance, she could make out layers upon layers of habitable floors situated within, including large round platforms where hundreds—if not thousands—of merchants and travellers congregated.
The rest of the city—an exceptional bulk of smaller, two-story structures and winding “streets”—must have belonged to the sea ponies. Rainbow saw evidence of this. The closer her gondola descended to its destination, she spotted entire schooling herds of equine shapes swimming through the outer ring of structures, several of them darting in and out of dark alcoves carved out of pure rock and sea coral. She lost count of how many citizens she saw, coming and going, working in shifts to reel in scores of fish or harvest resources from the nearby patches of anemone and kelp farms.
“Yeesh,” Rainbow heard herself exhale. “Do they even sleep?”
“Yes, albeit scarcely.” Theanim smiled. “At least by our scale.” He pointed at the dark depths looming above them, the gondola, and the lengths of Shoggoth. “The surface world's day and night cycle doesn't affect this seascape very much. The ponies down here have evolved to adopt a twenty-four-seven cycle.”
“What's that mean?”
“Oh... their bodies force them to take quick, involuntary naps every six hours or so. Their metabolism has adapted to this, and they're active most times of the day. As you can imagine, surface dwellers moving in to the habitable parts of the city have had to follow suit.”
“I didn't know our bodies could even do that,” Rainbow muttered.
Theanim chuckled. “Why, of course! I'm actually surprised, Miss Dash! A mare of your extensive travels? I'd imagine you would have adopted such a lifestyle ages ago.”
“I dunno...” Rainbow shrugged. “I've just... g-gotten used to be tired and crazy all the time.” She blinked. “Somewhere, my body found an awesome balance and I kicked flank the whole way through.”
“Mmmmff...” Echo grumbled. “Nocturnal is the way to go.”
Theanim rolled his eyes. “Thanks ever so kindly for your input, old chap.”
“I'm not just here for my good looks.”
“Oh goodness!” Rarity pointed out the porthole, jaw agape. “Look!”
“Huh?” Twilight craned her neck to see better. “What is it?”
“Just see for youself!” Rarity pointed, struggling to contain her squeals.
Rainbow squinted. At last, she saw through her spectral friends, spotting a sunken courtyard where several seaponies congregated. Bubbles rolled above them, forming a gentle cyclone. Then—in undulating clockwise motion—one seapony flickered after another, pulsing with multi-colored luminescence from head to tail, making all the fins in between shimmer.
“Why... isn't that the most gorgeous thing you've ever seen?!” Rarity cooed. “It's like... a whole 'nother language! And so beautifully simple too!”
“You seeing this, Doc?” Rainbow remarked.
“Indeed. That I am.” Theanim smiled. “Aquatic fire song.”
“Fire... song?”
“You think that bioluminescence is the only trick up this Tribe's sleeves?” Theanim chuckled. “The glow is merely a side effect of the effort it takes for them to produce melodic sonic vibrations. However, the sound seaponies produce is far too high a frequency for terrestrial ponies to make out.”
“Heh... what a cryin' shame,” Bard said, smirking. “What I wouldn't give to share some good ol' guitar twangs with these dudes.”
“Mrmmmfff...” Echo winced, his leafy ears twitching painfully. “It's not that melodic.”
“Oh... erm... r-right...” Theanim grimaced. “Sorry, old chap.”
“Oh no. It's quite fine,” Echo grumbled. “A splitting headache is the perfect cherry atop this pressurized shit sundae.” He rolled over on the floor, squirming in his binds. “...what I wouldn't give to go deaf right now.” Schoomf! Metal and flesh talons kindly shoved a canvas bag over his head. “... ... ...better,” Echo's voice emanated from within the muffling fabric.
Outside, Rainbow could see an entire district full of citizens lighting up. The fire song spread from one avenue to another, pouring through the alleyway, flowing from one building to another, then ebbing off into pixie sprinkles that faded along Shoggoth's fringes before eventually disappearing in a dull hush. Then, once that was done, the whole procedure gradually repeated, allowing a kaleidoscope of luminescent reverberations to ripple through the whole city yet again.
“Oh, it's absolutely gorgeous!” Rarity took a deep breath and plunged through the hull. “I'm going out for a better look!”
“Hey! Wait for me!” Twilight jerked after her, lingered, then smiled nervously back at Rainbow. “Y'know... s-scientific curiosity!”
“Mmmf...” Rainbow waved a hoof in the air. “Go. Fish.”
The mare leapt out, and Rainbow could faintly see both unicorns hovering several feet away from the port hull of the vessel, their bodies and manes undisturbed by the thick volume of seawater.
“What do you suppose they're singing about?” Rainbow asked.
“Hmmm...?” Theanim glanced over, blinking. “Oh! Uhm... at its most fundamental level, it's a way that the underwater herds have constantly kept a running tab on one another, from foals to full-grown adults. Sharing in the song allows for a sort of... collective subconscious in a way.”
“Yeesh...” Rainbow shivered. “Almost like changelings...”
“Almost like what?” Theanim asked.
“Do they ever sing to the sirens?” Rainbow remarked. “Like Camellia?”
“Mmmm... yes and no. It's more appropriate to say that she speaks to them.” He smiled warmly. “And when she does... hmmm... it's quite the heavenly sight to behold. Or—in this case—submersible. Eheh...”
“Why? Does she turn her subjects into a giant laser light show?”
“That's... one interesting way of putting it,” Theanim remarked. “Camellia has the ability to converse with the hearts and minds of any group of seaponies at any time. She doesn't need to... sequester them for a meeting like she needs to with terrestrial kind. It's quite fascinating, really. I sometimes wonder what it would be like to have a ruler who could read you like a book and vice versa.”
“I dunno.” Rainbow shrugged. “To me... it kinda sounds like the exact friggin' opposite of Queen Verlaxion.”
Theanim blinked, his ears drooping slightly. “That's... that's something I've never thought of before...”
Silence.
“You're looking pale, Theams,” Echo droned beneath the bag on his head.
“I... I am most certainly n-not!” Theanim huffed and puffed.
Rainbow smirked. She glanced out the window again at her floating companions.
Her eyes were drawn towards the tiny buildings of Shoggoth behind them. The undertrolley was nearing the end of its trip, and the bright amber haze of the city's largest domed structure drowned out most of the neighboring light. Even still—through a sliver of dark water—Rainbow Dash could sworn she saw the collective fire song of the city rolling towards her, taking on a pink hue at the very last second and exploding directly beneath her gondola like bright party balloons.
“Unnngh...” Rainbow slouched in her chair, rubbing her head.
Wildcard and Bard sat up straight, heads craned identically. “Hey, Missy.” Bard whistled. “Y'all okay?”
“I... uh... y-yeah...” Rainbow opened her eyes. There was a flash of red on yellow, and she bit her lip to keep from shivering. “Just...” She turned and stared down through the gondola's floor. Yaerfaerda loomed below... pulsating with vibrant intensity... as though it was just a few hundred meters away. “...just feeling the pessure, I guess.”
Bard blinked. Wildcard raised an eyecrest.
Th-Thoom! The entire gondola shook while every passenger on board wobbled.
Theanim exhaled, then stood up with a bright smile. “Well then.” He winked. “We're here.”