Hermione lifted her head, seeing he was staring at her, curiously waiting for her to voice her thoughts. "Dumbledore was dying then, presumably at least... and Snape... Do you really think he knew? But yes, he is a Potions master after all and he worked for years with dark ingredients and poisons; he must have at least spotted the signs and  maybe even put them together." She stared at the page in front of her again, feeling helpless. "If he had been cursed with some of the ones in the book, there is no way he hadn't shown any signs."