"Shh," Hermione said, dropping her books as she grabbed at Bellatrix’s mouth, pressing the witch against the wall of the owlery. "I don’t care that it’s a joke. You can’t say those things around here. If someone overheard, they wouldn’t know the context or...God they could work out the context and where would we be!" Hermione said, her hand still covering the witch’s mouth. "Promise me you won’t make a joke like that. Please. If someone works out who you are, you could get thrown into Azkaban."