Midnight Vigil. Ask the wrong pony about it, and you'll wake up in bed the next morning, with no memory of what you did last night. However, if you ask the right questions in the right places, you'll hear fantastic rumors about Princess Luna employing creatures like changelings and vampires. But don't worry. Luna's monsters are on your side, and their job is to protect you against the ones that aren't. They're pretty good at it, too. Most of the time.