"A publisher in New York asked me to write down what I know about the Greek gods, and I was like, Can we do this anonymously? Because I don't need the Olympians mad at me again. But if it helps you to know your Greek gods, and survive an encounter with them if they ever show up in your face, then I guess writing all this down will be my good deed for the week. So begins Percy Jackson's Greek Gods, in which the son of Poseidon adds his own magic--and...