A lockdown catches five grade 12 students by surprise and throws them together in the only nearby unlocked room: the boys' washroom. There's Alice: an introverted writer, trapped in the role of big sister to her older autistic brother, Noah; Isabelle: the popular, high-achieving, student council president, whose greatest performance is her everyday life; Hogan: an ex-football player with a troubled past and a hopeless future; Xander: that socially awkward guy hiding behind the camera, whose candid pictures of school life, especially those of Isabelle, have brought him more trouble than answers. When Isabelle gets a text that says NOT A DRILL!! Shooter in the school!, suddenly, the bathroom doesn't seem so safe anymore. Especially when they learn that one of them knows more about the shooter than they realized.