I really liked this book. It took me a while to get into the story, but after about thirty pages I couldn't stop reading!
The story is about a girl who, after being betrayed by a friend, doesn't want anything to do with society. She spends her days running and reading until one day, she meets a strange boy. They go on a date but things are more complicated than they seem..
I think of this as a really good book, however there are some things that my nerdy side would like to be explained. For example, how comes that every silhouette forgets about the time travelling person the next day except for Calla? In fact she's a silhouette too, for Valcas travels to her 'past'. Another thing that didn't really fit in the story to me is how much Calla trusts anyone she meets for the first time, even though she was betrayed by her friend.
On the other hand, my nerdy side fell in love with the way some of the aspects of the glasses were explained. I also really liked that even though Calla was attracted to Valcas, she wasn't blind for the mistakes that he made.
I would highly recommend this book to everyone that likes science-fiction.