Modern soul youth Qin An time-travels into the chaotic era of the Daxing Dynasty, where he is forced by the imperial court into a arranged marriage with Yang Yuyan, an exiled official's dependent with two daughters. He awakens the God of Killing System, growing stronger through hunting by acquiring vital energy. Guided by his wife and daughters, he masters military strategy and martial arts, eliminates enemies, fortuitously becomes a constable, goes into the mountains to annihilate Baiji spies, and is subsequently ordered to train militia. When the Eastern Expedition war breaks out, Qin An leads troops to enlist, performing repeated meritorious deeds on the battlefield and growing into a cavalry captain, able to briefly return home to reunite with his family before following the grand army to rush to the perilous front-line battlefield, striving to protect his family and comrades amidst the troubled times.