"What's weird, Fred?" inquired Angelina from across the locker room, where she was struggling with the laces on her armbraces. Given the sheer density of magic around Hogwarts, it wasn't exactly surprising that they had somehow developed a malicious tendency to re-tie themselves every time she tried to take them off, but it was still extremely annoying. "If you two are concerned, I think the rest of us should be - er - " She stalled out, looking like she wasn't totally sure what the appropriate solution was to something that alarmed the Weasley twins.