I think everyone who read carry on was expecting a happy book with Simon and Baz making out all the time, but Rainbow went so deep into the characters issues and showed the human side of them. During the first book Simon did everything that was expected from him, people wouldn’t stop talking about his purpose and what he was supposed to do, and now he has nothing. No magic, no prophecy to fulfill, he don’t know what to do with himself. That’s what wayward son is. Is Simon doing things just for the sake of it and not because he’s supposed to. Is Baz and Simon knowing each other as friends, no as enemies nor lovers. Is Penny being vulnerable and not knowing what to do. Is Agatha being her own person and not the Chosen One’s girlfriend. It’s about discovering who you are, dealing with real issues and being okay with not being okay.