The protagonist Chen Yuan (a cultural relic restorer) receives a mysterious bronze box from an archaeological site. On the box is engraved "It is neither gold nor jade, the key appears by itself; the responsibility of protecting the ruins is passed down from generation to generation." When he was repairing a damaged piece of Warring States lacquerware under a specific light, the light and shadow cast by the lines on the wall matched perfectly with the lines on the bronze box, forming the first map to the secret realm.
