“Swift70… may we rest for a while?” Felzein’s voice was low, his words heavy with the toll of their unrelenting velocity.
His eyelids drooped, wearied by the invisible weight pressing upon them.
The sheer intensity of speed gnawed quietly at their senses, as though the ocean itself whispered them into slumber.
“You poor things… You’re beginning to succumb to the effects of high-inertia stress and neuro-circulatory pressure fluctuation,” Swift70 answered, her tone tinged with a curious blend of concern and affection.
“What does that mean?” Cherlyn’s voice barely escaped her lips.
Though her lashes trembled shut, a flicker of curiosity clung stubbornly to her.
Felzein turned his head with effort and murmured, “Swift70, explain… for Cherlyn here.”
“Of course, dearest,” came the smooth, modulated reply. “The condition you are experiencing is known as Neuro-Circulatory Inertia Fatigue. At extreme speeds, your bodies are subjected to intense inertial forces and volatile shifts in neurovascular pressure.”
Cherlyn blinked slowly, “Pressure in the nerves… fluctuating?”
“Yes,” Swift70 went on gently. “Your brain’s electrical signals cannot adequately adjust to the surges of microgravity and magnetic turbulence. In response, the brain initiates a protective mechanism, an induced state of restorative drowsiness.”
Felzein nodded faintly, “And if we fight it…?”
“You risk disorientation, compromised awareness… even minor convulsions. But rest assured, the cabin’s equilibrium is holding steady. Close your eyes. Fifteen minutes will suffice to restore clarity.”
“Only fifteen?” Cherlyn breathed, her voice a sliver of sound, her gaze drifting toward the navigation panel.
“It can be longer,” Swift70 replied, voice low, almost maternal.
“But it is unwise. Prolonged sleep under unstable pressure disrupts your circadian rhythm and delays motor recovery. Fifteen minutes, no more. It is the precise measure your bodies need. No less, and certainly no more.”
Felzein drew a slow, measured breath, his eyelids growing heavy, “Fifteen minutes! A fleeting dream in the eye of a storm.”
“Very well,” he murmured, his voice low and slipping into slumber’s embrace. “Wake us when the time is done. No more than fifteen minutes.”
A beat of silence passed before he added, almost as an afterthought, “And one more thing! Expand your radar perimeter! I’ve a feeling we’re not alone beneath these waters.”
“As you wish, dearest,” came Swift70’s reply, her voice hushed and velvety, an uncanny echo of warmth born from circuits and code. “Radar field expanding now. Sleep soundly. I shall watch over you both.”
Scarcely had Felzein and Cherlyn surrendered to the pull of slumber when Swift70, ever vigilant, initiated the extended radar protocol.
The engines purred beneath the steel skin of the vessel.
Quiet, obedient, precise, responding with a grace more akin to a living creature than a machine forged by human hands.
The radar system stirred to life anew, recalibrating with clinical elegance.
No longer content with a mere perimeter scan, it now stretched its reach beyond ordinary bounds, casting an invisible net across the abyss with intensified frequency and sharpened resolve.
Electromagnetic pulses surged into the fathomless dark, threading their way through salt and silence, probing further, deeper, untangling the secrets veiled within the black cathedral of the sea.
At its core, Swift70 adjusted algorithms reshaped in real time, filters recalibrated, sensitivity heightened.
Its sensors evolved with every sweep, refining each return to discard illusion, discard echo, discard myth. Only truth remained.
The digital display blossomed before it, a cartography of motion and stillness, pressure and current, life and artifice.
Points of interest appeared like fireflies in the gloom. Some benign, others watched with colder scrutiny.
Now came the shift. Its scans no longer turned in passive circles but lunged outward with a hunter’s focus.
High-frequency bursts tore through leagues of ocean, gathering whispers of the world beyond, and bringing them back as revelation.
There was no faltering, no degradation of fidelity.
The harmony between machine and sea held fast, symphonic in its execution.
Everything, every distant tremor, every metallic displacement, every unnatural silence, was etched into Swift70’s mind with crystalline precision.
A three-dimensional projection bloomed in the heart of its interface.
Elegant, pulsing, alive. The sea was no longer an unknowable vastness. It was mapped, named, and tamed at least for now.
And within this cathedral of circuitry and sonar, two fragile lives lay still, shielded not by bulkheads alone, but by the quiet ferocity of their sentinel’s gaze.
Nothing would approach unnoticed. Nothing would touch them unchallenged. Swift70 watched. And she would not sleep.
*****
Meanwhile, far beneath the veil of the Pacific’s ink-dark surface, the Seiryū Maru, a sleek patrol submarine of the Japanese Maritime Self-Defence Force, cut through the water in utter silence, a phantom in the deep.
It was a marvel of modern naval engineering, armed with unparalleled weaponry and equipped with radar systems of almost preternatural acuity.
Its purpose was singular, to guard the sovereign seas of Japan against whatever spectres might stir in the abyss.
Below deck, in the subdued glow of the mess hall’s overhead lamps, a solitary figure lingered over a modest supper.
Officer Kaito Ishida, one of the younger crewmen, sat hunched over a steaming bowl of instant noodles, the rising vapour curling like ghostly fingers around his tired face.
He slurped the spicy broth with idle contentment, the sharpness of the chilli briefly cutting through the haze of monotony and fatigue.
Around him, the hush of the ocean's crushing depth was omnipresent, so still it seemed to press against the hull like the breath of some sleeping colossus.
From time to time, he wiped a hand across his face, chasing away the weariness etched into his eyes.
In that small, fleeting solitude, with only the muted hum of machinery for company, Kaito let his mind drift, untethered and weightless through the cold and endless dark.
Yet the silence did not endure...
BEEP! BEEP! BEEP!
The sharp cry of the radar alarm shattered the stillness, like the sudden crack of thunder across a windless plain.
Petty Officer Kaito Ishida jolted upright, the spoon of steaming noodles slipping from his fingers, splashing forgotten on the metal floor.
His moment of solitude dissolved into a haze of adrenaline and confusion.
He sprang to his feet, heart pounding beneath his uniform, eyes drawn instinctively to the glowing radar console.
What he saw there drained the colour from his face.
In the eerie light of the screen, a single moving object painted itself across the display, yet its speed was beyond comprehension.
Far faster than any submarine, any torpedo, any vessel known to exist.
“This... this can’t be,” Kaito whispered, voice trembling, as though the very act of speaking the thought aloud might summon some terrible truth from the deep.
“Captain! You need to see this now!” he shouted, urgency cutting through the chill air.
Within seconds, Captain Ryoji Takahashi appeared beside him, his boots echoing against the steel deck.
One glance at the radar display was enough. His calm demeanour faltered.
The anomaly was unmistakable, an object moving at a velocity that defied naval logic, carving a silent path through the ocean’s darkness directly toward them.
Kaito swallowed hard, his voice barely more than a breath, “That speed... there’s nothing in the world that moves like that.”
The room fell into a tense hush, pierced only by the quiet pulse of the radar and the steady rhythm of dread mounting in their chests.
Something unknown was stirring in the deep, and it was coming fast.
Captain Takahashi’s gaze lingered on the pulsing green glow of the radar screen, then slowly shifted back to the central monitor with a weight that drew the room into silence.
Around him, the crew began to gather, drawn in by the unnatural rhythm of the alarm, their faces pale beneath the cold fluorescent lighting.
A quiet murmur passed among them, but no words could soften what was now clear, this was not a drill, nor an anomaly easily dismissed.
“The object remains at a significant distance,” the Captain said softly, though each syllable bore the gravity of command. “Yet its velocity... it surpasses anything within our military knowledge.”
He paused, eyes narrowing as the data continued to stream in, “This isn’t just fast. It’s unnatural.”
“Could it be an aircraft?” someone ventured, uncertain. “Or something... else?”
Kaito, still standing rigid near the radar console, shook his head almost imperceptibly.
His voice, when it came, was tight with disbelief, “No aircraft could sustain such speed underwater, Captain. Not with current propulsion systems. This defies every known design.”
A hush fell once more as sweat traced silent lines down foreheads and along the napes of necks.
The hum of electronics, once ambient and familiar, now sounded ominous like the ticking of a clock counting down to something unseen.
The object continued to close the distance, each sweep of the radar rendering it nearer, bolder, impossible to ignore.
What had begun as a routine shift aboard the Seiryū Maru had transformed into an encounter with the inexplicable.
Within that pressurised hull, somewhere deep in the cold, dark embrace of the Pacific, the crew found themselves united not by protocol but by a growing sense of dread.
For whatever approached them now was not simply fast, nor merely foreign.
It was a riddle carried on the currents, and its answer was yet to be revealed.