The tremor lasted four seconds.
When it was over, a crack had opened in the south face of the mountain — a crack wide enough to walk into, which Yuna and her friend Dex proceeded to do immediately and without telling anyone.
The tunnel was smooth. Too smooth for something made by an earthquake. The walls were flat, the floor nearly level, the ceiling arched in a way that spoke of design, not chance.
"Someone made this," said Dex.
"A long time ago," said Yuna.
They walked for twenty minutes, their phone torches throwing long shadows. The tunnel sloped gently downward, then levelled, then opened into a chamber so large their lights didn't reach the far wall.
In the centre of the chamber stood a structure of stone — not rough-hewn, but precisely fitted, block against block, mortared and smooth. A building inside a mountain. A room no one outside had known existed.
The door was sealed. But the window — a narrow horizontal slot — was open.
Yuna shone her torch through.
Inside: vessels of fired clay. Tools of bone and metal. A floor covered in something that had once been parchment and was now only shape. And on the walls, covering every surface, lines of script that neither of them recognised.
They didn't touch anything.
They went back the way they came, walked directly to Yuna's house, and told her mother, who was an archaeologist.
They did everything right.
It didn't stop Yuna from going back in her dreams for years, standing in that sealed room, trying to read the walls.