After being taken hostage by an intimidating figure who insists that she marry him, Elena Zhao awakens in an opulent castle. He asks her the same question every night when he sees her: "Did you sign?" Elena is stuck despite her best efforts to flee; the head maid Linda is her lone friend. Elena becomes aware of her hazardous predicament when her cousin shows up and offers herself to her captor. Elena signs the marriage license in an attempt to keep herself from becoming a mistress and to get some control over her future. She aims to negotiate the treacherous route of survival, deceit, and hesitant acceptance as his lawful wife. However, to become truly a wife, she must at least who exactly he is.