Cha Myung-jun, a late-career sergeant who had to be confined to the basement of the Ministry of National Defense for more than 30 years because of his abilities that he awakened just before the war. After 30 years of being the world’s strongest blacksmith with only hammers, he deceives the eyes of the Ministry of Defense for the sake of the war and returns to the past. In his second life, will he be able to succeed in his campaign and save humanity from its destruction?