Although Seonho is not affluent, he leads a content life working as a regular courier. One day, he coincidentally crosses paths with Jun-goo, who used to bully him in high school, at a delivery location. Despite feeling relieved that Jun-goo did not recognize him, Seonho stumbled upon evidence of a murder in his house and realized he was a witness to the crime. Trapped by Jun-goo, Seonho is forced to work for him as a courier once again, similar to a decade ago.