In fact, the source of this iron has been clearly written in the notes of grave robbery, and a creature from the mountain is sealed in the iron block. As we know, some time ago, in order to help the stuffy oil bottle to retrieve its memory, Wu Xie and Fatty came to Bajiao, Guangxi, and found a sunken hut at the bottom of the lake in Yangjiao Mountain. There is a Gu Lou in the thatched cottage, and a large number of bronze figurines and jade mines are stored in the Gu Lou. The iron in the box is a part of the bronze figurines.
Inside the bronze statue, there is a humanoid monster in the mountains when mining iron ore. This monster is called Miruotuo, the ancestor of the Yao people. In the myth of Yao people, Miruotuo is their first goddess and also comes from the mountains. Monster is the prototype of Miruotuo, which is a very magical jade with the ability to synthesize human life. In short, it is to come back to life.
In fact, the tomb-robbing notes have also been explained. The main building of the Zhang family is the place where the bodies of the Zhang family are stored. Of course, in addition to the bodies of the Zhang family, there are clones made of meteorite copper in Gu Lou. As we know, in the TV series "Old Nine Gates", Buddha Zhang once came to Zhangjia Gu Lou to restore his true colors by cloning people. Obviously, the existence of human cloning is actually necessary.
Of course, if it weren't for the clan of the Zhang family, it would be absolutely impossible to come to the boundary of the Zhang family, let alone enter the Gu Lou of the Zhang family. In fact, anyone who dares to enter Zhangjiajie without authorization will be destroyed by the designed organs. In Old Nine Doors, when Zhang Qishan came to treat the disease, they could not enter the Zhangjia Gu Lou without Zhang Qiling's permission.
To sum up, Zhang Ge's iron hidden in Gu Lou can help Zhang Ge find his lost memory in the notes of grave robbery.