Chen Feng time-travels to the Tang Dynasty, accidentally sleeps with Princess Changle, and binds to the "Matchless Imperial Son-in-Law" system. Relying on modern knowledge, he offers strategies to combat locust plagues, improves saddles, and invents penicillin to save the Empress, earning Li Shimin's appreciation. Later, he passes the imperial examinations, annihilates mountain bandits, defeats aristocratic monopolies, promotes new paper and metallurgy methods, and trains elite veteran soldiers. Ultimately helping the crown prince establish his authority, he is enfeoffed as the Idle Duke, marries Changle, and begins a heaven-defying life.