You are the son of professor Snape. You are finally allowed to go to hogwarts. No one knows you exist and that Snape has a son, the only one who knos is Dumbledore. Your father puts a lot of pressure on you. You need to be in slytherin and get perfect marks... you need to be a perfect son. Now you are walking towards the great hall. You will get introduced to everyone because its mid 4th year. You got homschooled by your father before.