During the reign of Emperor Suzong of the Tang, the An Lushan Rebellion had yet to end after years of fighting. Lu Ziyue, a young man from the borderlands of Longxi, arrived in Chang'an, a city ravaged by war.
Hoping to serve his country and make a name for himself, he had barely arrived in Chang'an when he encountered the refined and graceful young woman Miaoyi and fell for her. Little did he know that this would land him in prison. Only then did he discover that many secrets lay hidden behind Miaoyi, and that the seemingly delicate young woman had a mysterious past.
From then on, Lu Ziyue became a swordsman in Chang'an, facing one strange and dangerous ordeal after another alongside Miaoyi. He had no idea that a vast conspiracy was slowly drawing him in. Were those around him friends or foes? Where did the mysterious force behind it all come from? A drama that would decide the survival of the Tang Dynasty was reaching its climax.