Modern ace combat engineer Chen Zheng died in the line of duty and opened his eyes again, only to find himself kneeling on the guillotine of an ancient execution ground—having become Xiao Dingbei, the young general who suppresses the North, accused of treason and facing the extermination of his entire family. Stop the execution! Using bronze seals to verify authenticity, breaking barriers at broken bridges, and improving heavy crossbows, with his modern combat engineer skills, he stubbornly defended a lonely city into the Great Wall of the northern border from a nine-death prisoner cart. Court impeachments were like knives, ten thousand enemy troops pressed the border, and a mysterious masked strategist closed in step by step. From a condemned death row prisoner to the military god of the northern border, he stood supporting the banner: This Yanmen, I will defend it to the end.