Yu Zhezhi, a nightmare demon burdened with three hundred years of accumulated sins, is punished by being sent into a book, where she becomes Jiang Lingyi, a vicious imperial consort destined for a tragic fate. Trapped in a deadly arson scheme in the Cold Palace, she faces one frame-up after another orchestrated by the seemingly innocent Song Wanyue. Using her wit, she fights back at every turn, tears away the mask of hypocrisy, and uncovers the truth behind the Jiang family's military provisions scandal from three years ago, clearing her family's name. Through their battles and growing companionship, she and the outwardly cold but inwardly warm Emperor Xiao Chengyin fall deeply in love with each other. In the end, she gives up her journey home and chooses to remain in the mortal world, spending her life with the one she loves.