What is Backstabber about?

Backstabber is about an innocent girl walking from the park to school due to a leaflet she found on a tree. She finds out she's very interested in what the leaflet says and goes straight to the school. The audience can see that someone is watching her but she has no idea and then it turns out when she goes to the school she is set up and then murdered by the mad guy in school. This mad guy also gets revenge on someone that walked into him so therefore it means he is bullied