The first swell of water had barely settled when Karl adjusted the ballast, letting the Pacific currents pull them downward. The sub groaned, hull plates flexing under the initial increase in pressure. Agnes hovered beside the main console, her holographic form soft but alert, eyes glowing with streams of data cascading invisibly as she calculated tolerances and stress points.
"Pressure's rising," she murmured, voice calm yet precise. "At this depth, the demons are going to start feeling it… but so are we. One wrong miscalculation and—well, the hull isn't exactly immortal."
Karl smirked faintly, tightening his grip on the nanite control. "Lucky I've got… me," he muttered, nanites surging from his drive regulator to reinforce every bulkhead, brace, and plate. The metal of the sub seemed to shimmer as the nanites interwove with the structure, reinforcing edges and redistributing tension with almost imperceptible pulses.
"Lucky indeed," Agnes said, floating closer to watch. Her hand brushed his shoulder briefly, a grounding touch amidst the hum of machinery and pressure. "You're doing an impressive job. But don't forget—you're not the only one keeping this thing alive."
Karl glanced at her. "Neither are you."
She chuckled softly. "Touché."
Outside, the water darkened, the sunless depths swallowing all light. The abyss was almost palpable, a pressure so dense it pressed against the hull like an invisible vice. The Abyssal Lampreys and Shoreline Gulpers from earlier had trailed them, but the increase in pressure slowed their movements, limbs trembling against the crushing force. Deepborn slithered through crevices but hesitated as the water thickened, and even the Fin Razors struggled to maintain their speed.
Karl's fingers danced over the nanite interface, sending pulses of reinforcement across the submarine's frame, watching the energy lattice flare as it absorbed and redistributed the crushing force. "Almost… there," he muttered. "Just a little more… a little more and they're going to regret ever following us down."
Agnes projected overlays onto the viewport, showing pressure curves, hull integrity, and the demons' likely behavior under increasing stress. "At this depth, even their bones start to buckle," she said, voice softening slightly, almost reverent. "But we still need to maneuver carefully. The sub isn't indestructible. It's designed for deep ocean conditions, not the abyssal extremes we're heading into."
Karl nodded, adjusting thrusters. "Understood. Reinforcing lateral supports. Nanite lattice… spreading evenly. Hold steady."
The sub shuddered under a sudden external force—one of the Abyssal Lampreys attempting to latch—but the nanites rippled along the hull like living metal, dissipating the impact before any serious damage occurred. Karl's breath caught for a second, then he exhaled, eyes sharp.
"They're… slowing down," he observed, voice tight but steady. "Pressure's doing the job."
"Yes," Agnes said, her holographic glow softening. "They won't follow much deeper. But the deeper we go, the tighter the next obstacle becomes. We need to start scanning for that underwater ravine—our escape route."
Karl flicked a lever, sending a nanite probe forward. It twisted through the darkness, scanning geometry, water density, and the ravine's dimensions. "I see it," he said after a tense moment. "Narrow. But long enough for us to hide—and… maybe shake them completely."
Agnes floated closer, fingers brushing his arm in reassurance. "You'll have to maneuver carefully. Hull clearance will be minimal. One slip, and we risk scraping the reinforced sides—could damage the lattice integrity."
Karl's lips pressed into a thin line. "One slip and they'll be inside me," he muttered dryly, though there was a spark of excitement under the tension. "Noted."
They began the descent together, navigating into the tight ravine. Water pressure increased with every meter, nanites responding instantly to reinforce weakened points, sending micro-adjustments along the hull. Outside, jagged rock formations loomed, twisting and curving in impossible angles, barely wide enough for the sub to slip through.
Agnes's voice was calm, guiding. "Tilt starboard three degrees. Increase port thruster output… steady… steady… don't touch the left bulkhead."
Karl obeyed, every muscle tense, nanites thrumming with energy as they redistributed stress from the hull. The sub scraped against a sharp outcrop, but nanite reinforcements flexed the metal enough to prevent damage.
"You're handling this perfectly," Agnes whispered, her voice carrying both pride and something warmer, softer. "I almost didn't think anyone could do this without practice."
Karl shot her a sideways glance. "And you think you could? Hologram or not?"
"I could," she said simply, a faint teasing note. "But you're making me look good."
He grinned despite himself. "That's what I do best."
"Indeed," Agnes replied, though her voice softened again. "But… I wouldn't be doing half of what I am if you weren't guiding the nanites. You're… steadying me, Karl. Keeping me from overcompensating."
They moved deeper into the ravine, walls twisting around them, the water pressure oppressive but stable thanks to Karl's constant nanite reinforcement. Even the Abyssal Lampreys and Deepborn couldn't keep up, pressing against the edges of the ravine and hissing in frustration.
Karl let himself relax slightly as they moved, tiny victories stacking: the pressure holding, the sub stable, the nanites flexing beautifully under strain. "We've come a long way," he murmured. "From burning streets in New York to this… under the Pacific. I never thought we'd get this far."
Agnes floated near his shoulder, her glow warming. "Almost a year," she whispered. "Since you… well, since you got here. Since we met."
He nodded quietly, letting the weight of it sink in. "Almost a year… and I'd do it all over again."
Her hand brushed his arm, reassuring. "I know you would."
They navigated the final bend, the ravine narrowing to a near-perfect tunnel, walls almost scraping the sub's sides. Agnes's overlays lit up with stress projections. "One wrong angle now… and we could compromise the hull."
Karl's nanites surged, flexing every reinforced plate and distributing stress as evenly as possible. "Trust me," he said, voice low and focused. "I've got this."
Agnes's smile was small but warm. "I do, Karl. I really do."
With a precise tilt and a series of careful propulsion adjustments, Karl guided the sub through the narrowest part of the ravine. Water pressure battered the hull, but the nanite lattice held firm, and the sub slipped through without a scratch.
Outside, the Abyssal Lampreys and other creatures pressed against the rocks, unable to follow. The Pacific deep swallowed them whole.
Karl exhaled, letting his shoulders slump slightly. "We made it."
Agnes floated closer, hand brushing his arm. "Together," she whispered. "Always together."
For a moment, the deep ocean was quiet, the oppressive weight of water pressing against the reinforced hull—but inside, Karl and Agnes shared a rare, victorious silence. They'd pushed past the demons, navigated impossible pressure, and threaded the needle of a tight ravine.
And somewhere deep beneath the Pacific, they allowed themselves a fleeting, quiet moment of triumph.