In the Tang Dynasty, there was a peerless military strategist and statesman, the Duke who safeguarded the nation. Lin Xuan, after transmigrating to the Tang Dynasty, leads 7,000 soldiers in white robes gifted by the system, defeating the Jieli Khan on the banks of the Wei River. His seven advances and seven retreats in the enemy camp earn him immortal merit, after which he hides in seclusion in Lantian. The court, to acknowledge his achievements, bestows upon him the title of Duke, but searches for him in vain. One day, a girl falls into the water in the county and is saved by Lin Xuan through CPR. Later, this girl frequently visits Lantian with a middle-aged man and a younger sister (Princess Linchuan). One day, the middle-aged man whispers to Lin Xuan, "Duke, I guessed it was you! My daughter quite likes you. Will you come out of seclusion and be my son-in-law? Become a prince, a prince with an additional title!" Main characters: Lin Xuan...