Wait For It
I watch him carefully, my eyes narrowed as he crosses the room. I've never liked him. Over the years, it's become a strong, mutual antipathy. But he doesn't see me now. No. For all his conceit, I'm far better at stalking than he.
He doesn't deserve her. She's the best of them; I'd never have spoken to her if she wasn't.
Ah. Here he comes; here's my chance. I tense in anticipation, preparing my attack. Wait for just the right moment... Now!
Snape roared as Crookshanks buried his teeth in his arm. "Hermione, get your thrice-accursed cat off me now!"