A modern young man accidentally transmigrates to a fictional dynasty, and becomes Arthur, a lowly Household Servant in a noble manor. Drawing on his unique knowledge of history and remarkable courage, he rises step by step from the bottom of the social ladder. He uses his quick wit to defuse a royal crisis, gets unwittingly drawn into the imperial princes' succession dispute, and uncovers the truth behind his family's massacre while investigating the mystery of his own origins. Amid plots and schemes, he repeatedly navigates out of tight spots using modern wisdom, learns peerless martial arts from reclusive masters, and forms a deep bond with Su Yue'er, a sharp and courageous female physician. From an ordinary street commoner to a master strategist, from a bullied Household Servant to a powerful high official respected across the court, Arthur holds fast to his principles amid the power struggles, ultimately avenging his family and upholding justice.