Jean Auguste Dominique Ingres La Grande baigneuse painting

You're going about it the wrong way," said Hermione. "Only you can get the memory, Dumbledore says. That must mean you can persuade Slughorn where other people can’t. It's not a question of slipping him a potion, anyone could do that —"
"How do you spell 'belligerent'?" said Ron, shaking his quill very hard while staring at his parchment. "It can't be B — U — M —"
"No, it isn't," said Hermione, pulling Ron's essay toward her. "And 'augury' doesn't begin O — R — G either. What kind of quill are you using?"
"It's one of Fred and George's Spell-Check ones, but I think the charm must be wearing off."