A detective finds herself reincarnated as a villainess in a romance novel. Seo-hyun was chasing a serial killer who targeted web novel authors. Just before catching them, she fell—only to wake up inside a novel as a doomed villainess obsessed with the male lead. But the story goes off track. The male lead changes, the crown prince becomes obsessed, and even the commander starts pursuing her. Meanwhile, murders similar to her past case begin happening in this world… and the real killer may have reincarnated too.