A teenage girl is raped and murdered. Seven months later, the lack of progress in the investigation compels the girl’s mother to come up with an idea that would shake up the whole town. Mildred Hayes rents three abandoned billboards to send a message to the police chief William Willoughby. Despite multiple threats, Hayes refuses to take down the billboards. As the local authorities bring in new people to deal with the matter, Willoughby is found dead! Has the mother gone too far or does this imply a new threat to the town?