On the day he was demoted to the frontier army, Xie Zhao detonated the imperial city gate and exploded the three-story palace wall, shocking the world. The world called him crazy, but Liu Yanqiu, a female general in the border army, discovered that the explosive formula was consistent with her late father's relics. Zhao Chongli, the Minister of Civil Affairs, secretly pursues him, but Bai Wujiu, a spy from Beidi, wants to join forces with him to forge a weapon to destroy the country. When Shen Tieyi's bronze medal and Su Yunheng's banned book appeared one after another, a firearms conspiracy that had been buried for thirty years was slowly revealed - what he blew was not the door, but the backbone of the Dajing Empire.
Xie Zhao went into exile in the north after blowing up his door, and Liu Yanqiu was forced to accompany him. During the pursuit, the two gradually discovered that the "Xuan Tielei" technology originated from the forbidden technique of the former Ministry of Industry, and that the royal family secretly exported ordnance every year and was cooperating with Bai Wujiu. In order to protect his official position, Zhao Chongli repeatedly set up traps, but secretly hid the "Firearms Atlas" in the border army's granary, intending to lure Xie Zhao to take it for himself. Shen Tieyi finally confirmed that Xie Zhao's father was killed by the royal family and began to secretly mobilize troops to intercept the pursuers. Su Yunheng stole the fragments of the "Tian Ji Lu" and revealed that the gunpowder formula on the day of the bombing was composed by Xie Zhao using his father's relics, in order to make the murderer appear realistically. The three team up to sneak into the underground weapons warehouse of the imperial city, only to discover that the real mastermind is actually the current prince - he wants to use the hands of foreign enemies to detonate the capital, frame Xie Zhao as the blame, and proclaim himself emperor. Xie Zhao and Liu Yanqiu led the remaining troops to counterattack, but Bai Wujiu defected before the battle, and sacrificed his life to paralyze the detonation system. The ending stopped when the prince activated the final 'Earth Dragon Thunder', and in Xie Zhao's hand, there was only the last fuse with the words 'Father's unfinished ambition' engraved on it.
