storytelling party

I am responsible for hosting a storytelling party! I am a little bit terrified! It's on the second floor, so I can't serve alcohol. The good side is that I don't have to find a co-host who is willing to take turns keeping an eye on the alcohol. The bad side is... how am I going to lure people in? Nice foods, I suppose. But how do you decide how much foods to have, when you don't have any idea how many people might come?