Crossing over into a magical world, Luowei is slapped with a capital crime for "impersonating a nobility" right at the start! While others bitterly study magic, she uses mathematics to crack magic runes, relies on modern technology to improve wool, and does business to support knights, turning a poor life into an overpowered journey. But as a demonic swordsman draws his sword for her and a royal princess tests her step by step, the secret of her identity behind her black hair quietly surfaces—this time, what she wants to reclaim is not just barren land, but a new world belonging to herself!