On December 13, 1937, Nanjing fell. On the evening of that day, on the Japanese blockade on the southern border of Zijin Mountain outside Nanjing, a reborn soul rose from among the corpses. He came from the future—a grassroots of Chinese folk Brain King. Because of a tiny clue, he was awakened, and his superiors gave him a difficult task. Relying on complex calculations and extraordinary IQ, Grassroots Brain King designed a whimsical plan with extraordinary perseverance. Plan, he is like a sharp knife, firmly nailed to the devil's heart!