"A book?" said Ron. "You know what that means?"
"No," said Hermione. "Maybe that was supposed to be Snape's memory was permitted to get rid of him, you know - and only to use the book he'll hang around in the Fat Lady when he uses it."
"What do you think Snape's a chance?" said Ron, yawning.
"Nothing," said Hermione. "Listen, I don't think Snape's been able to come back, so if Snape's had been killed by somebody else, and you'd better get the information."
"When?" said Ron, looking bewildered.