Percy was quietly trying to remember the wand movements for a Reductor Curse, which he'd passed over briefly in his Defense textbook but not learned as it wasn't on the official OWL syllabus. Fred awkwardly stepped into the white bishop's space, making a vague go away! gesture at it; Percy could swear that the bishop actually raised an eyebrow at Fred. He said, "Fred, you may want to duck?", and then aimed his wand and prayed he was remembering correctly. "Reducto!"