Kate had been born in a vault.
She had grown up there. As for the outside world, Kate had only heard about it from her parents and teachers. Honestly, she had never had any particular yearning for that world supposedly ravaged by nuclear bombs. Her wish had been simple: like her father and grandfather before her, she wanted to spend her life peacefully in the vault, get married, have children, and grow old.
Unfortunately, reality and dreams were always two different things.
The vault was attacked.
Kate did not know exactly what had happened at first. She only knew that someone had tricked the vault's overseer into opening the heavy circular iron door. Then a group of strangely dressed, bandit-like men rushed in. They looted the entire vault, and anyone who dared resist was killed. The rest were rounded up like livestock and taken away.
At the time, Kate had thought that was hell. But it had not been that simple. The day after they were taken away by those terrifying bandits, a group of soldiers clad in strange armor and wearing fly-like helmets raided them. They mercilessly shot the bandits dead, then began capturing the others all over again.
In the end, Kate's companions from the vault were either taken away by the bandits or seized by those terrifying monsters in fly armor. Only she escaped under cover of night and made her way to this town of Rolling Stone.
The people here were fairly kind. They took in Kate, who had nowhere else to go, and gave her a decent job. But Kate did not want to simply live like this. Her younger brother and sister had also been taken away, and all she wanted now was to find them. To that end, she had asked around everywhere.