"She's got more sense than just about anyone," Ron said, eager to jump on any alternative to Hermione's idea. "If we can make her understand it's what has to happen ..." He trailed off - if she didn't want to be made to understand, of course, they'd be completely out of luck. It was something of a risk. But it was better than just telling Snape. "We should at least tell her as much as we tell him."