The ravine finally began to open up, the stone walls pulling back just enough to give the submarine room to breathe again. Karl eased the thrusters down, letting the vessel drift for a moment as the current carried them forward. Outside, the darkness shifted—less claustrophobic now, but deeper somehow. Older.
Agnes tilted her head, gaze fixed on the abyss beyond the viewport.
"…You know," she said softly, "every time I look at water this deep, humans start whispering myths again."
Karl glanced at her. "That sounds ominous."
She smiled faintly. "I was thinking about Atlantis."
He blinked. "Atlantis?"
"Mhm."
He let out a small breath, half a laugh. "Okay, I didn't expect that one to come up down here."
Agnes folded her hands behind her back, drifting slowly in place. "It always comes up down here. The ocean does that. Makes people think about what might be hiding beneath them."
Karl nudged the controls, keeping them steady. "Wasn't Atlantis supposed to be somewhere near the Mediterranean? According to Plato, I mean."
"Yes," Agnes replied. "A powerful, advanced civilization. Sunken in a single day and night for its arrogance." She paused. "At least, that's the version humans told each other."
Karl raised a brow. "You saying there's another version?"
"I'm saying myths are usually distortions of something," she said gently. "Especially when they persist for thousands of years."
He glanced at the black water again. "You think it was real."
Agnes didn't answer immediately. Her light dimmed slightly, thoughtful. "I think… it's statistically unlikely that an ocean covering over seventy percent of the planet contains no lost civilizations."
Karl hummed. "When you put it like that…"
"Humans reached the stars in theory before they fully mapped their own oceans," Agnes continued. "There are trenches deeper than Everest is tall. Entire mountain ranges underwater. Ruins could exist down here and never be found."
"And now," Karl added quietly, "there are demons."
Agnes looked at him. "Exactly."
They fell silent for a few seconds, the hum of the submarine filling the space between them.
"So," Karl said slowly, "Atlantis… demon city? Ancient super-tech? Or just a bunch of really unlucky people?"
Agnes smiled, teasing returning to her tone. "Why limit ourselves to one option?"
He snorted. "Of course you'd say that."
She drifted closer to the viewport, eyes glowing faintly as if trying to see through kilometers of water and time. "Imagine it, Karl. A civilization that mastered energy, architecture, maybe even something like Vythra—long before your world ever dreamed of it."
His fingers tightened slightly on the controls. "And then something wiped them out."
"Yes," she said. "Maybe a natural disaster. Maybe war. Maybe something from below." She glanced at him. "Or something from elsewhere."
Karl grimaced. "You're really selling the 'don't explore the deep ocean' argument."
"And yet," Agnes said sweetly, "here you are. Reinforcing a submarine with nanites and diving into pressure zones."
"…Fair."
She turned more serious again. "There's another possibility too."
"Oh?"
"Atlantis might not have been destroyed," she said. "It might have left."
Karl looked at her sharply. "Left where?"
She shrugged lightly. "Deeper. Or sideways. Or into something adjacent to reality. Civilizations with enough understanding of energy don't always die. Sometimes they… relocate."
"That's unsettling."
"I know," Agnes said softly. "But also kind of hopeful."
Karl considered that. "You think something like that could still be down there? Watching?"
Agnes met his eyes. "If it is… it would know about the demons. About the surface collapsing. About you."
He chuckled nervously. "Great. Another audience."
She smiled, fond. "You get used to it."
The submarine drifted past a sheer underwater cliff, lights sliding over stone that looked almost carved—too smooth in places, too symmetrical.
Karl frowned. "Tell me that's just erosion."
Agnes scanned it for half a second, then tilted her head. "It is… probably erosion."
"Probably."
"But," she added quickly, "not Atlantean. No energy residue. No structural logic. Just geology being dramatic."
Karl relaxed a notch. "Good."
She leaned against the console beside him, voice lowering into something more intimate. "You know why humans loved the idea of Atlantis so much?"
"Because secret cities are cool?"
"That too," she said, amused. "But mostly because it meant they weren't alone in being brilliant—and flawed. Atlantis was a warning and a comfort at the same time."
"A warning about what?"
"About rising too fast," Agnes said. "About believing mastery means immunity. About thinking the world owes you survival."
Karl stared ahead. "Sounds… familiar."
Agnes's expression softened. "Yeah."
They continued forward, the submarine slipping silently through the deep like a thought the ocean hadn't noticed yet.
"If Atlantis existed," Karl said after a while, "and if it fell… you think we're heading the same way?"
Agnes didn't answer right away. She reached out, resting her hand lightly over his shoulder—cool nanites, steady presence.
"I think," she said carefully, "that the difference is you're not pretending you're invincible."
He smiled faintly. "I get knocked through walls too often for that."
"And you don't face the abyss alone," she added.
Karl glanced at her hand, then at her. "Neither did Atlantis, probably."
"No," Agnes agreed. "But they might not have trusted each other the way you trust me."
He let out a small breath. "I do trust you."
"I know," she said softly. "That's why I'm still here."
The ocean pressed in around them, ancient and unknowable, full of myths that might once have been real.
Somewhere far below, trenches yawned open like scars in the Earth.
And above them, the world burned.
But for now, inside a reinforced shell of steel and nanites, Karl and Agnes moved forward—carrying stories older than history and hope stubborn enough to survive even the deep.