Crossing over to the Great Tang, Li Hong was trapped in the mountains for seven years by a check-in system, mastering the arts of a divine doctor and the strength of an overlord, wanting only to live a carefree life with his family. During a road interception to collect money, he accidentally saved Empress Zhangsun, unaware that he was the imperial couple's eldest son who had been separated for many years. Knowing the truth, the imperial couple dared not recognize him rashly, and could only protect him in secret. Stepping into Chang'an, Li Hong offered grain to cure locusts, met friends through poetry, and angrily resisted nobles to protect his sister, becoming embroiled in the struggle between aristocratic families and the imperial court. When the bandit youth took charge of the Xuanjia Army, the secret of his identity also stirred the imperial family's deepest hidden grief.