Snape takes Harry's book and Harry goes to the staff room to get it,where he see's Snape's leg covered in blood. Harry heard Snape talking about the monstrous dog. Harry suspected that Snape was hurt by it. Hermione, Ron, and Harry were convinced that Snape was trying to get what ever the three-headed dog was guarding. Harry plays in his first Quidditch match, Gryffindor vs. Slytherin. During the game Harry's broom goes out of control. He thought Snape was behind this. Harry still catches the Snitch and wins the game for Gryffindor. Harry, Hermione, and Ron ask Hagrid what Fluffy(the three-headed dog)was guarding. Hagrid said that it was between Nicolas Flamel and Dumbledore.