Charlie kneels in the center of the floor, sitting back on his heels, his notebook open across his lap. His pencil scrawls frantic lines across the page. The tip of his tongue pokes from the corner of his mouth—a habit left over from boyhood—as he concentrates, muttering to himself in a rapid, breathless stream.
Bianca slouches against the wall, her grease-stained overalls half-unzipped over a floral blouse. A pencil skewers her messy bun at a crooked angle. She picks at a hangnail, bored.
SLAM!
The sound ricochets off the high, ancient stone walls. Bianca glances up, unimpressed.
Charlie jabs a finger toward the ceiling. "I have got it!"
Bianca's gaze slides toward him. The rest of her doesn't bother to follow.
Charlie clears his throat—Ahem!—and launches into a full dissertation. Bianca exhales through her nose, eyes rolling toward the ceiling, as he barrels on.
"Whoever sealed this passageway during the Void Century wasn't trying to lock a gate—they built an acoustic quarantine engine! Look at this outer circumference chiseled into the rock. Seven concentric circular tracks with microscopic electrum wires strung through living Sea-Stone and Pyrobloin composite. That is a textbook Monochordia Mundana. The entire thesis is that the cosmos is tuned by the hand of God through pure Pythagorean ratios! If you hit this door with brute physical force or an explosive shell, the kinetic shockwave gets caught in those electrum wires, divided mathematically into octaves and fifths, and dissipated straight into the continental plate! The harder you punch it, the denser the vitrified salt becomes! You're just feeding its inertia!"
He gulps a breath, eyes gleaming behind his wire-framed glasses.
"And that's just the dampener! Look inside the outer ring! See that heptagonal relief carved seven inches deep into the obsidian? That's the Sigillum Dei Aemeth—the Seal of God's Truth! It's exact sacred geometry! Look at the outer perimeter—forty glyphs chiseled in pure script and filled with crushed sea-pearl! The celestial hierarchy isn't decorative; it's an elemental vacuum lock! The characters around the four quadrants invoke Air, Fire, Water, and Earth. It is actively stripping the spiritual medium out of the air in the corridor behind it! Why? Because Tot Musica is an acoustic demon! A vibrational parasite that feeds on human perception and consciousness! If there's no etheric medium, sound can't propagate, and the demon stays blind, deaf, and functionally dead!"
He drags a sleeve across his damp forehead.
"Which brings us to the real problem: how do we break the Seal of the Veiled without blowing our own eardrums into jelly? You don't use a keyhole. You have to execute the fixation of the volatile and the dissolution of the fixed! It's an alchemical three-part fugue in contrapuntal motion!"
Bianca stares at him. Not a muscle in her face moves.
"To dissolve this Vitriol-Pyrobloin gate, one must sing three distinct musical keys simultaneously to trigger acoustic cavitation! First, a deep sub-harmonic drone in D Minor—the grounding tuned to the natural 432 hertz pitch to neutralize the Sea-Stone lattice. Second, an ascending, rapid vocal line in F Major to pull the static boundary into fluid motion. And third, the counter-melody in B-Flat Major! Why B-Flat? Because in Pythagorean music theory, B-Flat is the exact interval required to resolve the lethal tritone! If you don't hit that B-Flat, the ward activates and the characters will turn your own vocal frequencies inward until your lungs collapse!"
He leans in, his voice sinking to a hush, as though the floor might overhear.
"And the terrifying part? The climax! You don't just hold the chord. At the final measure, the singers have to deliberately introduce that minute microtonal discrepancy of twenty-three point four-six cents where twelve pure fifths fail to equal seven octaves! The perfection of the crystal matrix can't absorb a mathematical imperfection! The electrum wires will overheat, the obsidian channels will flash phosphorescent white, and the entire stone wall won't shatter—it will literally melt into a waterfall of emerald liquid vitriol, revealing the descent into the abyss!"
Charlie rocks back on his heels, chest puffed, thoroughly pleased with himself.
Bianca doesn't bother to sound interested. "Like cool. Or whatever. So, like, we like have to like sing to it and stuff."
Charlie weighs this, his gaze drifting sideways. "A rudimentary assessment. But yes."
Bianca pushes off the wall. "So like how do we like do that?"
Charlie's shoulders sag. "That is the real puzzle, isn't it."
Bianca blows out a long breath, and her eyes roll again. "Like whatever."
She digs into her pocket and pulls out a brass-plated Baby Den Den Mushi. Its transceiver horn rattles violently against her palm.
Charlie brightens and springs to his feet. "Yes! Of course!"
Bianca shoots him a withering look. "Like chill."
---
On the bridge of the Pluton, Jean Bart looms over a console, his massive hands working the controls with a watchmaker's delicacy as he tracks Elegia's power fluctuations. Readouts stutter across the screens—energy spikes, seismic tremors, the slow, distant throb of Tot Musica's form.
Jean Bart glances back at Clione. "Status on the Thalassa."
Clione answers, "Holding steady. Their AI is adjusting to environmental drift."
A console chirps. Uni calls out, "Incoming communications."
Jean Bart orders, "Put it through."
Bianca's voice crackles over the comms. "Like yo."
Uni leans toward the mic. "We hear you loud and clear."
Bianca continues, "Like cool. We like need some help with like music and stuff."
Jean Bart, Uni, Clione, and Hakugan trade puzzled frowns.
Hakugan asks, "Music?"
Bianca confirms, "Like yeah."
Charlie's voice cuts in, tight with urgency. "Specifically harmonic resonance—"
Bianca snaps, "Like chill! Like don't confuse people and stuff." A pause. "Anyway, can you like get Vesta? We probably will like need the AIs too, so like can you like bring Halia and Melinoë online so we can like coordinate? Charlie will like be better at explaining to them than me."
Jean Bart nods. "Understood."
---
Out on the Pluton's deck, Vesta leans against the railing, her rainbow hair glinting in the dream world's strange, hazy light. She watches Tot Musica's silhouette warp and flicker on the horizon—a colossus stitched together from shadow and sound—while she sips from a bottle of water.
The hatch bangs open. Clione steps out and waves her over. "We need you on the bridge."
Vesta blinks and points at her own chest. "Me? I don't know anything about the bridge."
Clione shakes his head. "Bianca is on the line. They need some help with music or something."
Vesta straightens, eyes going wide. She pushes off the railing. "Oh!"
She hurries in after Clione.