Chen Xiu's broken arm can detect the most dangerous weapons in the world, but cannot detect the evil in people's hearts. When a rusty sword that can "drink blood and reveal secrets" draws him into a family murder case twenty years ago, he is forced to become the "iron judge" of the world - blood is needed to solve the case, and only after all the blood has been shed can the truth be known. The six-fingered beggar, the poisonous widow, the brocade-clad Zhuan An... All the dead are missing a finger on their left hand, and Chen Xi's broken arm is the final key to unlocking the mystery of the Yin soldiers' escape.
