In order to find out the truth about her sister's mysterious death in the palace, Su Muyan, the daughter of the Chancellor, entered the palace draft in her place. However, due to her upright personality, she repeatedly violated palace rules and was assigned to work in the cold palace. In an abandoned palace, she encounters a mysterious man who calls himself "Flower Father-in-law", but is actually Hua Zhuyue, the deposed prince who disguises himself as an eunuch because he is tired of the power struggle. The two of them performed a "fantastic" daily life in the cold palace, from testing each other to gradually developing feelings for each other. When Su Muyan discovered that her sister's death was related to the struggle for imperial power, and Hua Zhuyue was actually the key person she wanted to investigate, the relationship between the two fell into crisis.
