Shen Zhe, a graduate student in history, travels through time to the Great Yan dynasty and becomes a live-in son-in-law of the Su family, only to discover that his entire family of in-laws consists of fellow time travelers. To protect himself, he conceals his identity and secretly resolves crises using his supposed "native wisdom," navigating a treacherous path from aristocratic monopolies to imperial power struggles. Working from within and without with Su Qingyu, Shen Zhe supports Prince Murong Sheng of Fanyang in ascending the throne, completing the grand plan to "slay the dragon." After the new dynasty is established, Shen Zhe retires at the height of his success and withdraws to Jiangzhou with his wife. Suspicion between ruler and ministers leaves a lingering aftertaste.