I finished this one, the second in his science fiction trilogy. As with the first one I looked on line for some enlightenment on exactly what it was all about. I got the Adam and Eve part but his twists on the story left me wondering what he was trying to tell us. Here is a good explanation from a religious point of view and here is the Wikipedia page. I think I could really read these several times, esp. this one to get everything out of it. Lewis's writing is difficult for me at times. So the last book takes place on earth, no more space travel. I'm kind of sad about that, because that was the part I liked the best. His imagination is very fascinating.