Billy absolutely LOVES Nature Girl. She's his favourite superhero EVER! He has read all the books, seen all the cartoons, and he's even got his own Nature Girl costume! So when World Book Day comes round, Billy knows exactly who he wants to dress up as. Then Billy hears a nasty voice in his head. What if he looks silly? What if his friends make fun of him? Going out in a costume can be scary, even if you are dressed up as your favourite character in the whole world. Can Billy be as brave as Nature Girl?