Well. Maybe you can start it off with the main character going to a circus with friends. You can have them watch the show, and then afterwards they find a circus freak killing somebody. My advice, is to not jump into action so quickly. There needs to be information describing her, the way she looks, how old she is, why they're going to the circus, her friends names etc. Before the action starts, you want the reader to feel like they have a relationship with the main character, and her friends. That way, if something tragic happens, they feel closer to the main character and more shocked by say the death of a friend.
