Sean McLoughlin was a regular 12th grade student. He had barely any friends, he had good grades, and he made sure most of his work was turned in. He thought his last year of high school would go by without any bumps.
But that dream stops when there are five days left of school, and his homeroom teacher has a substitute. Mr. Fischbach.
Sean suddenly realises that these last five days are going to be interesting.
[Forgive me for being cliché]