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.
                                    Shin Hye-sun
Jang Soo-hyun
                                    Kim Sung-kyun
Joo Cheol-ho
                                    Kang Tae-oh
Na Seung-hyun
                                    Lee Zoo-young
Oh Dal-ja
                                    Lim Cheol-soo
Chief Im
                                    Geum Sae-rok
Kim Hye-jin
                                    Im Sung-jae
Delivery Man
                                    Kim Kwang-hyun
Detective Lee
                                    Jo Yong-jun
Detective Kim
                                    Jeon Jun-young
Student
                                    Noh Young-hak
Student
                                    Choi Jae-sup
Worker
                                    Shin Seung-yong
Worker
                                    Jung Woo-young
Invitation Man
                                    Byun Jin-su
Forensic Team
                                    Jeong Da-eun
Employee
                                    Kimchoi Yong-joon
Police