Severus Snape. He is a dark man, anyone could see that by the way he dressed, and acted, and by the subject he favored from the very start of meeting him. The people around him never thought to look beneath the glares and the snark, especially those who knew that he had been a Death Eater from those who had lived through the first war. But Hermione knew all too well than to simply judge a person's character by what others thought, or how their outward appearance seemed. Tom taught her that better than anyone. Harry didn't trust him, accusing him of anything and everything going bad in the castle, especially of trying to steal the Philosopher's Stone Dumbledore had been guarding.