Martha Macdonald is in trouble. If she doesn't pass enough O.W.L.s then her dad has decreed that she will not be coming back to Hogwarts for her N.E.W.T. years. For Martha, returning to Hogwarts is essential or her dream of playing professional Quidditch will disappear faster than the Snitch at the start of a match.
Perhaps if she'd studied instead of flying, then she wouldn't be in this mess. Maybe if her boyfriend wasn't the distracting Sirius Black, then her brains wouldn't turn to mush as soon as she bent over her textbooks.
Or, says a small voice in the back of her head, perhaps she's just stupid.
Will Martha scrape an Acceptable or will she always be a Troll?