[Hardcore + Textual Research + No Golden Finger] History teacher Lin Yuan woke up and traveled through time to become a helpless clerk in Wuyue Kingdom. At this time, Qian Hongchu had just been put on the throne by powerful ministers, and the Central Plains Dynasty in the north was sharpening its sword. While others traveled through time and space with systems and warehouses, Lin Yuan only brought with him a head full of historical lesson plans and observation skills developed in the workplace. Faced with the realistic predicament of "first south and then north" unification and partial peace, others see a dead end, but he sees an opportunity - because the law of historical development is never determined by one or two wars or three or five weapons.