On the day of Princess Royal Li Lanyu's wedding, General Xun Hengyu, the Guardian of the Nation, unexpectedly brings another woman into his residence, using his military power to force her to accept the woman as his equal wife. Li Lanyu has already laid out an elaborate plan. With the late emperor's golden decree, she mobilizes troops and publicly exposes Xun Hengyu's crimes of murdering fellow generals and plotting treason, uncovering Prince Rong's collusion with foreign enemies. Before the internal turmoil can be quelled, Southern Chu's hidden agents seize an opportunity to cause trouble. Li Lanyu lures the enemy step by step, setting a trap that severely damages Southern Chu's army, while remaining vigilant against Northern Di. The struggle between the imperial court and the frontiers continues.