I love that they go from GQuuuuuux to Eight. 8 would be more minimalist. GQ title reminds me of a cat running through the keyboard. Anyway, is the protagonist male this time? I'm still waiting for a storyline with a set of identical twins (don't care what gender).

A lack of faith is honestly a valid reason for Susan not to return to Narnia since the book series was based on Christianity. C.S. Lewis was associating Susan with people that are raised with or "know the message," but end up rejecting it eventually. It's pretty much stated in the Bible (which influenced the series) that not everyone will make it to heaven.

It goes a long with the message "not of this world (Earthly desires)," and Susan definitely preferred to be in the human world. Having faith like a child is another message, and Susan had too many doubts to stay true to Narnia.

It would be a disservice to everyone in Narnia if someone tied to the Earth, where magic is impossible, returned only to have doubts or possibly not see anything. Really, Susan stopped seeing Aslan during Prince Caspian. Those without faith can't see the magic of the other side that is Narnia.

Susan could have her own spinoff of her life on Earth. If she was able to forego her logical nature, she probably could return to Narnia. Like Lewis's own , some people do return to the faith they had when they were children.