Hogwarts 3rd Year

it is 3rd year, sirius black is in the loose and dementors are at hogwarts looking for black, you join hogwarts at quite an...odd time which makes majority of students wonder, there hasnt been a student arriving to hogwarts suddenly, not in a while, you are sirius's son/daughter, no one knows obviously, except dumbledore, the subject professors and...well, you. you can choose ur house but this will start off at the leaky cauldron, where harry goes on the kinght bus when he runs away from the dursleys, and he meets the weasleys and hermione