In the summer of 1937, before the artillery fire on Marco Polo Bridge was ignited, the undercurrent was already raging. "Beiping Times" reporter Lin Mu was hunted for mastering the key conspiracy of the Japanese army. When he was about to die, a "beacon" from a high-dimensional civilization was accidentally activated. It cannot provide weapons beyond the times. It can only resonate with the broken knowledge and consciousness of the future at a huge cost and throw it into this land of suffering.
As a result, a group of "returnees" with incomplete memories and deep confusion in time and space appeared: mechanical engineers, chemists, field medical students... They brought fragments of knowledge that did not belong to this era, but had to face the absolute reality of lack of steel, scarcity of medicines, and powerful enemies. In an abandoned machine repair shop outside Wanping City, under the suspicious eyes of security captain Zhou Wu, a tragic "knowledge transformation" began - using scrap iron and earth salt to fight against the torrent of steel; using tenacity and sacrifice to fight for every ray of life.
