Soo-hyun, who has recently moved into a new house, buys a used washing machine through a second-hand app but finds out it doesn't work. Annoyed by the seller's irresponsibility, she leaves a comment calling the seller a con man, and reports it to the police. Little does she know that the seller is a psychopathic serial killer who uses an online second-hand market to lure his victims. Her comment renders his hunt for a new victim all but impossible so she becomes his next target. She starts receiving obscene phone calls, countless unwanted food deliveries, and strange men knocking on her door looking for a good time. A trip to the sender's address proves deadly serious when the police and Soo-hyun find a man’s dead body.

Don't Buy the Seller

Park Jae-sang was a royal geomancer, who helps people designate propitious site for houses, store and even graves under the belief that a grave in a good site will bring future fortune for descendants. But he loses his family because he exposed a conspiracy about crown Prince's grave site. Park Jae-sang plans to make a revenge of his family and learns that there is a much bigger conspiracy about propitious grave site; the place that would make grave owner's son the King of Joseon.