Hermione is tired of Professor Snape picking on her and the rest of the Gryffindor's. She feels that they are being mistreated and on a particular day when she was already angry from the morning she had had. Professor Snape yells at Neville for messing up on yet another potion and takes points from Gryffindor. Harry outraged stands up and gets even more points taken away and even a weeks worth of detention. Hermione opens her mouth and is forced to take Harry's place.