Libby (Charlize Theron) has a tragic childhood. Her mother and two sisters were killed by a perverted killer and died in a pool of blood. Libby escaped luckily. After that, she stood in court and identified her brother Ben (Corey Stoll) as the culprit. Ben was imprisoned for this. This tragedy caused a strong response in the society. People wrote letters to donate to Libby, the poor girl. With these donations, Libby grew up. However, the shadow of the past turned her into a woman who did nothing all day and abandoned herself. As time goes by, Libby is gradually being forgotten, she receives fewer and fewer donations, and her living conditions are getting worse and worse. At this moment, a young man named Lyle (Nicholas Hoult) finds her and spends a lot of money to invite Libby to the "Killer Club". Under the instigation of the club's weirdos and Lyle, Libby begins to review the case she has been avoiding, and some doubts gradually surfaced.