"What my Nayeon knew what to do best was to keep secrets. But, I was much better at revealing them."

After being hired to investigate the rich businesswoman Im Nayeon for murder, detective Yoo Jeongyeon goes undercover as an aspiring novelist named Bang Eunkyung, in hopes of getting closer to her suspect. Easily attracted to her, Im Nayeon opens the doors of her mansion to detective Yoo, who soon finds herself in a dilemma; to arrest Im Nayeon, or to cherish her.

Through her narration between past and present, between Bang Eunkyung and Yoo Jeongyeon, the detective explores her struggle of falling in love with the woman she is trying to arrest, whilst questioning her morals as an officer.