Peter and susan aren't the last ones to leave Narnia! What happens is that aslan tells peter and susan (in the episode prince Caspian) that tis will be their last trip to Narnia this is because they are getting to old Lucy and Edmund do have a couple more trips there.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.