The evening before Harry's first Quidditch match, he sees Snape receiving medical attention from Filch for a bite on his leg caused by the three-headed dog. During the game, Harry's broomstick goes out of control, endangering his life, and Hermione notices that Snape is staring at Harry and muttering. She dashes over to the Professors' stand, knocking over Professor Quirrell in her haste, and sets fire to Snape's robe. Harry regains control of his broomstick and catches the Golden Snitch, winning the game for Gryffindor. Hagrid refuses to believe that Snape was responsible for Harry's danger, but lets slip that he bought the three-headed dog and that the monster is guarding a secret that belongs to Professor Dumbledore and someone called Nicolas Flamel.