Evelyn O'Brien is a vibrant and popular 17-year-old high school student. With her charismatic personality and striking looks, she naturally draws people towards her, making her a central figure in her school's social scene. Her twin brother, Dylan O'Brien, shares her popularity. Dlyan is part of a tight-knit group of friends, among whom Thomas Brodie Sangster stands out as one of his bestfriends. One day, during one of their group's regular games, Thomas end up losing and is subjected to a dare....