Lin Chen, a top modern history major and a seasoned strategic expert within the establishment, suddenly died of overwork while studying historical records of the Zhenguan era of the Great Tang. He is reborn back to the third year of Zhenguan in the Great Tang, becoming a down-and-out scholar from a humble family in the streets of Chang'an who suffers from bullying and the loss of his family. In his past life, he witnessed firsthand the corruption of governance, the monopoly of noble families, border crisis, and imperial shackles beneath the flourishing Zhenguan era. In this life, relying on his millennium-ahead cognition, modern statecraft thinking, and political maneuvering skills, he rises step by step from the bottom as an ant: breaking noble families, reforming governance, pacifying border crises, supporting a wise monarch, setting national policies, and ultimately becoming a chancellor at a young age, wielding immense power in the Great Tang. He assists Emperor Taizong of Tang in creating a prosperous Zhenguan era far exceeding the history books, becoming the greatest commoner of all time.