Harry finds a black notebook on the girl's bathroom floor. Curiosity invades his 12 year old body. He opens it in a random page and starts reading. He notices every S letter has the shape of a little snake.

Dear diary,

If theres one thing i was made for in this world is this: hate.
Hate fills my lungs. Hate is the reason i wake up each morning. My one and only dream is to live in a world were everyone shares the same hate for each and every being. Hate is, simply, what i do best.
The thing is, dear diary, life isnt always the way you want it to be. For every high there's a low, and mine is that there's times where i find myself not hating. Not at all.
Like friday's quidditch game for example. Quidditch is one of my favorite extracurricular activities. Nothing like a bunch of losers flying around chasing and running away form spheres to bring my loathing to its maximun levels.
So I stood there in the front row and the game started. Usually that's the time when I start cursing and making the most delightful faces of disgust but this time i got distracted by something, im not quite sure what it was, and found myself almost enjoying the moment.
It was an awful experience, i can't speak of it without making my stomach turn. I never felt so embarrased in my whole life.
I hope no one saw me, dear diary. I left the place as fast as i could, but im not sure, i think some ravenclaw girl saw me.
Maybe ill torture her later just to even the scales.

T.M.R.