Morning came to Kyoten crisp and bright. Dew beaded on grass like a scatter of tiny mirrors, and the first sunrays slipped across the village square, waking lantern paint to a sleepy shine. Doors opened with familiar creaks. Voices rose, warm and ordinary—vendors setting out baskets, a broom whispering across wood, someone laughing at a bad joke that was somehow better in the morning.
Aiko sat on the stone rim of the square, arms around her knees, eyes on the end of the road. Kenji leaned against the wall beside her, looking the same way, arms folded, calm as always.
"He's late," Aiko murmured.
Kenji adjusted his glasses, the ghost of a smile tugging at his mouth. "It's Pulsebun. Were you expecting punctuality?"
"A little," she said, though her smile gave her away.
A rhythmic metallic rattle cut across the square. Both of them turned.
"I'm here!" Pulsebun announced, hustling into view under the world's most ridiculous backpack—huge, bulging, with tools and coils peeking out like curious snakes. He took two determined steps, listed to the left, corrected, and puffed up proudly.
"Pulsebun," Aiko blinked, "are you moving out?"
"These," he declared, patting the mountain of gear, "are the essentials for a serious expedition."
Kenji arched a brow. Wire, hooks, jars, and what looked suspiciously like a portable lightning rod quivered in a nest of rope. "You won't carry that for long."
"You underestimate my stamina," Pulsebun said, bravely tightening straps that had already given up. "Also, I packed snacks."
Aiko stood, dusting stone grit from her palms. "If you faint in the first ten minutes, I'm not dragging you."
"Correction," Pulsebun said, pointing grandly at himself, "I am self-propelling. Additionally, I am highly conductive and therefore streamlined." He took one step and nearly tipped backward. "Very streamlined."
They left the quiet square and the safe geometry of the village streets behind. The path narrowed to a track worn by hooves and habit, then to a suggestion of one. Trees gathered overhead, calming the light to a steady green. The air cooled and deepened; the noise of Kyoten folded into the forest's hush, replaced by birdsong and the peppery scent of crushed needles underfoot.
Pulsebun led the way in spirited zigzags, the backpack swaying with alarming confidence. "Left is definitely left," he announced. "And right is a suggestion."
Aiko hopped a thick root, steadying herself with a hand against the bolted bark. "Have you been out here before, Kenji?"
"No." He scanned the trees, measured his breath, and looked down at the faint track. "Most people avoid this side. They say there's nothing—just old trees and stubborn rocks."
"So far," Pulsebun said, "we've seen at least eight excellent rocks."
Aiko's laugh slipped out before she could stop it. "You're only excited because you heard 'ancient world' and decided you might find a new toy."
Pulsebun's ears twitched, tiny sparks popping. "You know me too well."
Kenji paused behind them, unrolling a small map and pinning it with his thumbs to the hard light. "According to the record, we should cross a shallow run-off, then the ground rises. After the rise, the brush thickens. That's where the mentions start—'structures of stone and metal.'"
Aiko chewed on the phrase. "Stone and metal. Together."
"Not usual," Kenji said. "Most of what we build is wood, clay, brick. The documents suggest something… different. As if the builders weren't making a place to live, but a place to do."
"Do what?" Pulsebun asked, genuinely curious.
Kenji rolled the map and tucked it away. "That's the part they never say."
They walked. The path thinned to light and promise. Aiko's breathing found a rhythm with the forest; her pulse matched the hush of branches and the soft thud of her sandals on packed earth. She thought of the bakery—the oven's steady glow, her father humming as he shaped a loaf—and of the promise she'd asked for the day before: If it's too strange, we turn back. The words felt like a hand she could hold.
"Tell me again," Aiko said, "about the ancient world."
Kenji's voice lowered as though not to disturb something sleeping between the trees. "There are accounts older than any village, older than the Guild's first ledgers. They describe people who used light as easily as we use fire. They built machines that weren't alive, yet moved and listened—tools with minds of their own. Messages flew without paper. Doors obeyed without hands. Power ran like water, invisible but everywhere."
Pulsebun trotted backward a few steps, walking while watching their faces. "Machines like V-Monsters of the machine type?"
"Similar," Kenji said. "But not living. That's the part I can't reconcile. We bond with V-Monsters. We learn them; they learn us. The records make it sound like they had things that learned without hearts."
"That's creepy," Pulsebun decided, and almost tripped over a root. He righted himself with a heroic flail. "I prefer my genius with personality."
"What happened to them?" Aiko asked, soft.
Kenji's answer was a breath. "No one knows. The records end. Whole ledgers go blank. Stories turn to rumors, then to cautionary tales. It's as if—"
"As if someone erased them," Aiko finished.
He met her eyes. "Exactly."
They climbed. The trees grew older here—trunks thick with time, roots like sleeping dragons. The light broke into coins across the floor of the world. Every so often Pulsebun would stop and lean forward at some fascinating nothing, ears quivering like antennae, then dart on again, the straps of his backpack whispering complaints.
The ground rolled beneath their feet and then, without fanfare, it rose all at once. On the far side of the low ridge the air felt different—emptier somehow, as if a held breath had just been released. Kenji lifted a hand.
"Wait."
Aiko came to a stop, heart suddenly too loud.
"What is it?" she asked.
Kenji didn't answer. He pointed.
At first she saw only trees and the stubborn green of undergrowth. Then her eyes adjusted, and shape stepped out of the camouflage. Not a boulder, not a fallen trunk—the edges were wrong for that. The thing crouched among the roots and shrubs like a buried ship: surfaces too straight for forest, angles that argued with the wild.
Pulsebun inhaled sharply. "That is not a rock."
"Agreed," Kenji said, voice clean with awe.
They pushed through a last screen of brush. The forest parted like hair under a careful comb, and there it was: a structure, or what had once been one, asleep in the green. Metal—Aiko could feel it even before she reached out. Not the bright, shouting kind she'd seen in tools and buckles, but old metal, quiet and heavy, scabbed with rust and patience. Stone and metal together, laced with moss. Vines threaded through ribs of beam and broken column. The earth had tried to eat it and failed, leaving it half-swallowed.
Aiko's breath fogged in the cooler air poured off the ruin. She took a single step closer. The place felt… attentive, somehow. Not alive—but not ordinary either, as if it remembered what it was for.
Pulsebun set his backpack down with a grateful groan and crept forward, pawing at a shard. "This isn't like any alloy I've seen," he said, voice soft, like a kid in a temple. "It's too smooth where it should have pitted, and the rust is… behaving." He glanced up with a grin. "If I can take the tiniest sample—"
"No dismantling the mystery," Aiko said, though she couldn't quite keep the smile out of her voice.
Kenji circled a tilted slab that might once have been a door. It lay half-buried under soil and leaf fall, a massive rectangle with a lip along one edge and a long groove worn into the ground beside it. He crouched, studying the groove.
"It didn't swing," he said. "It slid."
"Automatic," Pulsebun chimed. "Probably. Look—the side is more worn. And this groove—perfect track. With… power."
Aiko gave him a look. "And you know this because…?"
"Because doors that go shhhh are cooler than doors that go creak," Pulsebun said gravely. "Also because of the groove."
Kenji stood, wiping dirt on his trousers. "If it slid, it needed a mechanism. If it needed a mechanism, the mechanism needed—"
"Energy," Aiko finished, a soft echo of the word that had been following them all morning.
They stepped closer together, the three of them. The forest seemed to lean in too, curious.
"What now?" Aiko asked.
Kenji scanned the fractured lines of the wall—half mural, half diagram. Symbols wandered there like rivers frozen in metal. He reached without touching, tracing the air over them. "We look," he said. "We don't take. We try to understand. And if something argues with us, we listen."
Pulsebun nodded, for once solemn, then brightened a heartbeat after. "I brought a lantern," he said, already fishing in his pack. "The good one that doesn't overheat. Much."
Aiko laughed, nerves smoothing just enough to take one more step. She laid her palm against a panel cool as deep water. A prickle ran up her arm, not painful—more like the moment just before a storm when the world decides whether to breathe in or out.
She drew her hand back, eyes wide.
"Did you feel—" she began.
"—that?" Kenji said at the same time.
Pulsebun's ears flicked. "What? I didn't feel anything, which is rude. If there's electricity, I should get to feel it."
Aiko let the breath go. "Maybe it's just nerves."
"Maybe," Kenji said, though his gaze had gone thoughtful, faraway. He stepped to a gap that might once have been an entrance and peered inside. Cool air flowed past his face carrying the dry tang of old metal and dust. "It keeps going."
Pulsebun flicked the lantern to life, a clean glow gathering under glass. "Adventure clause," he said, offering light forward. "We take two steps in. If it's bad, we take three steps back."
Aiko swallowed. The ruin hummed in her bones in a way that didn't require ears. She thought of the promise she'd asked for and nodded.
"Two steps," she agreed.
Kenji raised the lantern a fraction. "Together."
They crossed the threshold the forest had failed to swallow, and the light drew long, quiet lines across a floor that had been waiting a very long time.
Somewhere behind them, the morning kept unfolding. Somewhere ahead, something else did, too—old as rust, new as breath.
They didn't know it yet, but the past they'd come to visit had already turned to look back.