Programmer Song Yan travels back in time and becomes the live-in son-in-law of the Great Qian dynasty. Right from the start, he is falsely accused of stealing government silver and bound to the execution ground to be beheaded. At the critical moment, an AI large language model accompanies him through time, taking the form of an intelligent assistant named Roubao. With the AI's extraordinary computing power, he strikes back against the powerful minister Su Junchen, solves a smuggling case in the Ministry of War, persuades frontier generals to switch sides, and repels an army of 300,000 northern barbarians. He rises from a live-in son-in-law facing execution to become the first prince of a different surname in Great Qian.