Not sure if this is in the plot area, but what about an idea I have of writing a book in a book? It's about a person (Jane Average) who has a compelling message to tell and decides to write a book (can be a prologue thing). Then in an Epilogue she is reflecting about the why, what and how (kind of "after thoughts"). Both Prologue and Epilogue are short (few pages). What do you guys think about this? Too complicated or a nice twist?