The final book of the Milkweed Triptych. LOVED this series. It really made you think. Think of time as we know it, and how it could be and the possibility of changing things, not necessarily for the better or worse, just... changing it.
I really enjoyed Ian's writing style and how he was able to describe something that has never existed in a way that you could actually picture it in your mind when you read it.
If you enjoy the concept of time travel, you really need to give this series a chance. You're sure to enjoy it!