The mining city never slept.
Beneath the mountain, the air vibrated with the soft hum of blue crystals embedded in the walls. Wooden and metal bridges hung over glowing chasms lit by rivers of light, while houses, carved into the rock like nests, spread upward in layers toward the darkness of the cavern's ceiling.
Among the crowd of miners and apprentices, he walked.
A worn backpack hung from his shoulder, and blue crystal dust stained his beige pants and black sneakers. He had no rank. He had no class. He had no control over mana.
He only had curiosity.
The safe mines were the only places he was allowed to enter.Or so everyone believed.
There were no high-level monsters there. Only small creatures that fled at the sound of pickaxes and the constant murmur of workers. It was where ordinary people extracted basic blue crystal—enough to keep the city alive, but far from the pure power found in dungeons.
He wasn't interested in common crystals.
He was interested in what no one else was looking for.
He knelt beside a crack in the rock, where the blue light grew faint. His fingers brushed the stone, sensing a strange pulse—almost as if the mountain itself were breathing.
He frowned.
It wasn't ambition that drove him to search for something different.
It was frustration. The certainty that if he stayed there, he would spend his entire life between the same walls, breathing the same dust, never discovering what lay beyond what he was allowed to know.
"You're not supposed to be here…" he murmured.
The supervisor's whistle shattered the moment.
Shift over.
The walk back home was quick.Too quiet for a city that never slept.
His neighborhood lay on one of the lowest levels of the mining city, where the lights were dimmer and the walls far older. He opened the wooden door carefully.
"Mom?" he called.
Silence.
The house was tidy. Too tidy.
An envelope rested on the table.
His name was written on it, in a firm handwriting he had known since childhood.
He opened it with trembling hands.
Son,
If you're reading this, it means I'm not there to explain what comes next.Put on the necklace. Do not take it off. Ever.
It is not an ornament. It is a promise… and a key.When the crystal reacts to you, leave the capital. Do not wait.
Do not trust ranks. Do not trust those who claim to protect you.I didn't… and it was a mistake.
Forgive me for leaving you with this burden. I had no other choice.
—Your father
Inside the envelope lay an old chain.
And at its center…
A green crystal.
It didn't shine like the blue ones.It didn't glow.
It watched.
The moment his fingers touched it, the air grew heavy.
The crystal pulsed.
Pain.Light.
He clutched his face, gasping, and rushed toward the reflection of a crystal panel embedded in the wall.
His left eye was still red.
His right…
Was green.
And deep within the mountain, beyond sealed dungeons and doors no one dared to open, something stirred.
Above, in the capital, the castle bells began to ring.
They did not announce a celebration.
And as the echo spread through the tunnels of the mining city, a silent and inevitable question began to take shape:
What had just awakened… and why had it responded to him?