Yoshiro blinked hard. "Man-made?" He shook his head. "No way. That's impossible."

Kenji stomped his feet, kicking up snow. "I swear I'm not crazy. Just... come look, okay? It's just past that ridge."

Himeko stepped forward, adjusting her goggles. "We should check it out. Even if it's not man-made, any cave could provide valuable geological data."

Finally, a chance to study something beyond endless snow and ice, she murmured. It was getting boring

Yoshiro nodded, his beard frosted with ice. "Alright. Takeshi, you're with us. The rest of you, keep the camp running."

As they trudged through the snow, he turned to Kenji. "Alright, Kenji. What exactly did you find?"

"It's huge," Kenji said, his words coming out in puffs of steam. "The entrance is round, really round. Like someone took a giant ice cream scoop out of the mountain."

Ice cream scoop? Yoshiro suppressed a smile. This kid's been out in the cold too long.

Takeshi snorted. "Kid, you sure you're not seeing things? This cold can mess with your head."

Great, he grumbled internally. Another wild goose chase. We should be focusing on the princess's project, not chasing fairy tales.

"I know what I saw," Kenji insisted. "You'll see for yourself in a minute."

As they crested the ridge, Yoshiro stopped in his tracks. Several team members stood before a colossal black opening in the mountainside, its edges unnaturally smooth.

Impossible! How could we not have known about this?

Himeko pushed past him, her jaw dropped. "No way. This can't be real."

The cave entrance towered above them, dwarfing even the tallest buildings in the Land of Snow. Its perfect circular shape stood out against the jagged, snow-covered rocks surrounding it.

This defies everything I know about natural cave formations, she thought, her scientific curiosity overriding her disbelief. What was needed to create this?

Takeshi ran a gloved hand along the edge. "Huh. The kid was right. This ain't natural."

I'll be damned, he grunted internally.

Yoshiro turned to the group, his leader instincts kicking in. "We need to investigate. Himeko, Takeshi, Kenji, you're with me. You guys, stay here and keep watch. If we're not back in two hours, get help."

Kenji fidgeted with his backpack straps. "You think there's anything interesting in there?"

"No idea," Yoshiro said, checking his flashlight. "That's why we have climbed the mountain." And maybe to change the future of the Land of Snow.

They entered the cave, the howling wind fading behind them. Their flashlights revealed strange patterns on the walls, too regular to be natural.

Himeko ran her fingers over the surface. "These patterns... they're not random. It's almost like..."

"Writing?" Takeshi finished, squinting at the wall.

Unauthorized reproduction: this story has been taken without approval. Report sightings.

"Maybe," Himeko said aloud. "But not like any writing system I've ever seen."

The narrow tunnel suddenly opened into a vast chamber. Their flashlights couldn't reach the ceiling, the beams swallowed by the darkness.

Kenji whistled, the sound echoing. "This place is huge!"

A sharp yelp broke the silence. He spun around to see Himeko kneeling on the ground, brushing away loose rocks.

"Himeko? You okay?" he asked, moving closer.

She looked up, her eyes shining with excitement. "Look at this!"

In the beam of her flashlight lay a massive skull, its eye sockets as large as dinner plates.

"Whoa," Kenji breathed. "Is that a monster?"

Himeko shook her head, gently brushing dirt from the fossil. "No, it's... it's some kind of ancient creature. Look at the jaw structure, the teeth positioning... This creature... it doesn't match any known species."

Takeshi knelt down, examining the skull. "Those teeth... whatever this thing was, it was a predator. And a damn big one at that. Glad it's just bones now."

As they explored further, more fossils were found on the cave floor. Himeko darted from one to another, her earlier caution forgotten in her scientific excitement.

"Coral fragments here... and look, these are definitely marine arthropod remains," she said, holding up a fossilized shell. "This entire area must have been underwater at some point."

Yoshiro frowned. "But we're miles inland, and at high elevation. How's that possible?"

Kenji piped up, "Could it be plate tectonics? Like, the land moved?"

Himeko nodded approvingly. "Good thinking, Kenji. That's certainly part of it. But the scale here... it's huge."

As they ventured deeper, the fossils became more numerous. Yoshiro watched Himeko and Kenji dart from fossil to fossil. Like kids.

"Hey, check this out!" Kenji called, holding up a strange, spiral-shaped fossil. "What do you think this is, Himeko-san?"

She hurried over, carefully taking the fossil. "Fascinating! It looks like some kind of cephalopod, but the structure is all wrong. The chambers are... wait, is that a serrated edge?"

"This doesn't make sense," Himeko mused aloud. "These features don't belong together. It's like looking at an evolutionary impossibility."

Yoshiro cleared his throat. "Let's try to stay focused. We need to-"

"Yoshiro!" Takeshi's gruff voice echoed from further ahead. "You need to see this!"

They hurried forward, flashlights bouncing. The beams illuminated a sight that stopped them in their tracks. Enormous piles of bones and shells stood before them, arranged in neat, deliberate mounds.

Himeko's scientific detachment cracked. "That's... that's not natural. Someone arranged these."

Yoshiro approached one of the mounds, picking up a bone fragment. He rubbed the bone's edge with his thumb. "Huh. Look at this," he said, holding it out. "These are tool marks."

"Tool marks mean intelligence, but who... or what... made these cuts?"

Kenji leaned in, squinting at the bone. "You're right. It's too clean to be from teeth or claws."

Takeshi picked up another bone, examining it closely. "Same here. Look at these grooves. Whatever did this, it was sharp and precise."

Himeko took both bones, comparing them side by side. "The cuts are consistent. It's not just random damage. These were deliberately butchered."

Kenji's eyes widened. "But... that's impossible, right? Humans couldn't have been here back then."

"Not humans," Himeko said slowly. "But something... intelligent. Something that used tools and organized these remains."

Takeshi grunted, kicking at the ground. A small object skittered across the cave floor. He bent to retrieve it, holding it up to the light. "What's this?"

In his palm sat a small, green pentagon. Its edges were slightly worn, but the shape was unmistakably artificial. The smooth, delicate texture suggested a material similar to talc.

"This ain't no rock..."

"Let me see that," Himeko said, reaching for the object. Takeshi handed it over, and the others crowded around to get a better look.

Himeko turned the pentagon over in her hands, her eyes widening. "This is... incredible. The precision of these angles, the smoothness of the surface..."

Yoshiro leaned in, his breath fogging in the cold air. "It's not natural, is it?"

Himeko shook her head, still staring at the object. "No way. A pentagon is far more complex than circles or squares. You don't see this in nature."

Kenji's voice was hushed with awe. "Could an animal have made it?"

"Unlikely," Himeko replied. "This level of geometric understanding... it suggests an intelligence comparable to humans."

The group fell quiet, each lost in thought about what they'd found. Before Takeshi could speak, a cold blast of air cut him off.

The wind brought a foul smell with it. Rotting and dank, it hit them like a wall. The cave went dark for a second as their lights sputtered.

"Ugh!" Kenji coughed and pulled his collar over his nose. "What is that smell?"

Takeshi's hand moved to his weapon. "Smells like something died. Recently."

Yoshiro held up a hand for silence, straining his ears against the whistle of the wind. "Everyone, stay alert. That smell could mean-"

A distant sound echoed from the depths of the cave, cutting him off. It might have been the wind, or falling rocks, or... something else entirely.