What happened?

Dan is an outcast in school. His only friend being PJ Ligouri. Most people didn't talk to him, afraid he might yell at them. Most kids think he has anger issues, some know what he used to be like. But none know his present life. Where he goes after school, what he does for a job, or what his family is like. But Dan didn't exactly have a family. Or a home. Well, if you could call a secret hide out in the woods a home. But rarely, Dan asks himself one question. "What happened?"
What happened to that happy little curly haired boy who was always cheerful and had many friends? What happened to his loving family and safe house?
But then one boy, a new boy, came to his school. Phil. Phil had heard the gossip on Dan.
"Don't go near him,"
"He's dangerous,"
"He's not the same,"
"Ignore Dan Howell. That's the best thing you can do,"
But what happens when Phil approaches the un-approachable?