Ernie Burroughs cares about one thing: being funny. After graduating high school, he devotes his days to posting videos of his act online, waiting to get discovered. When his dad insists he either go to college or get a job, Ernie offers a compromise: he'll join a youth theatre group. His dad agrees under one condition: he cannot quit. Ms. Reddy, the theatre's charismatic director, instantly senses something special about Ernie and casts him as the lead of her upcoming "group-devised" production. Ernie is thrilled until he realizes the play will be about a school shooting and he will be playing the shooter. Gradually, the play infects his life, his mind and his relationships. He grows suspicious of the world around him, believing that something sinister behind the scenes is manipulating him toward an inevitably violent end.