The Northern Suppression Female General Huo Changying returns in triumph, yet is bestowed in marriage to the sickly imperial prince Pei Shi'an, who is eight years her junior. She thinks she has married back an imperial court spy, but little does she know that this little prince, who calls her "older sister" at every turn, is actually the unfathomable master of the Tingxue Pavilion. To investigate the old military grain case from ten years ago, the two go from probing each other to falling truly in love, yet successively fall into crises of treason framing and palace upheavals. She lifts her spear to break through enemy formations, while he sets up schemes to protect her, joining hands to expose the powerful minister's conspiracy. When the old case is finally vindicated, a letter brings astonishing news: Huo Changying's father, who went missing for ten years, is actually still alive.