The spell HAD to be in this book. When Josephine switched bodies with Barry, he had found himself in her apartment and in her body holding this book. It had taken Barry a bit of time to figure out what had happened -- after all, no one expects to suddenly be in someone else's body -- but he had put the pieces together soon enough. He was, however, having a hard time reading the book. Most of it was in a language he simply didn't understand. He'd have to bring it to someone, but he was sure the spell to swap bodies was in here. He'd use it and get his body back!