I'm a science fiction fan, and most of the time I hate it when mainstream writers write on science fiction subjects. Certainly a book about time travel is a science fiction subject. This time, however, the mainstream writer did a very good job with the subject. I think she has done her homework.This is basically a love story with a mystery attached. It was a very enjoyable read and I think would appeal to people who enjoy an unusual premise, but also appeal to people who normally wouldn't read a book about time travel. You find yourself caring about both the main characters and the situations they are in, and you are rooting for them to find a way out of their predicament.