Chen Jing really was just a book of music, originating in the State of Chen during the Southern Dynasties. After the State of Chen fell, Chen Jing naturally ended up in the hands of ordinary people. Several centuries later, a legendary martial arts master found it. He had only meant to use its melodies to ease his fatigue after practicing martial arts.
Unexpectedly, during that time, the old master learned a sword technique hailed as the best under heaven. When the technique entered the world, it sent shock waves through the martial arts world. Every powerful martial artist wanted to obtain it.
The old master who created the sword technique did not want it to fall into outsiders' hands. He hid the manual in the mountains, in caves, in beams, and at springs... but martial arts masters found it every time.
Theme: Recover the secret manual.