24-year-old web novel writer Won Yeong isn't interested in love, but she can't help admiring her roommate's handsome boyfriend, Shin Mu-il. But Mu-il suddenly dies, and Yeong receives a mysterious package containing a robot vacuum. The vacuum introduces itself as an AI copy of Mu-il, and claims that he was murdered. Now, Yeong must navigate life with a digital version of the one man she couldn't resist, as she's pulled into a mystery far stranger and more personal than any of her novels.