It's midnight. After an unsuccessful try to fall asleep, you've decided to take a walk in a corridor to fresh up your mind. Unfortunately, after 15 minutes of walking, you notice Professor Snape. You're trying to silently walk away, but he sees you and says sarcastically with distaste "Oh, someone's looking for extra time in my office. I can assure you that on my detention you'll have enough time to satisfy your need to see me. Now, follow me, Miss."