"Sit. Down." Snape's quiet voice was dangerous in his wrath, his nose flared. Harry stopped in his tracks, breathing heavily, and turned to face Snape. "You are not dismissed until I say you are. Professor Dumbledore has ordered you to learn Occlumency, and to learn it from me, and that is what you will do. I. Do not. Care. Whatever other obligations you think are important, you will arrive here on time, and you will practise each night. Is that clear?"