In her previous life, the orphan Lin Shuyue was used as a pawn for revenge by her enemy, Gu Xuanzhi, and ultimately met her death beneath the sea. Reborn with the memories of two lifetimes, she launches a powerful comeback, outwitting her rivals in the inner household and forging an alliance with Su Hua, Shen Zhiyao's lover. Following clues left behind by the deceased, she travels far to Jiangnan to uncover the truth behind the Lu family's massacre and the old case involving the Marquis's residence. As the villain Zhang Chongyi closes in with a deadly ambush, Gu Xuanzhi takes an arrow meant for Lin Shuyue, sacrificing himself to protect her. In his final moments, he resolves a twenty-three-year-old misunderstanding with his birth mother, Chen Lanyin, over why she abandoned him. In the end, Lin Shuyue clears her name, takes control of the Marquis's residence, raises her son Lu Nianheng, and finally lets go of the love and hatred that haunted both her lifetimes amid a sea of twilight mist flowers.