I'd say this book needs 3.5 or 3.75 stars, rather than a full 4, but only because there were a few gaping plot holes that I felt like I had to overlook in order to fully buy into this story. Other than that though (I won't spoil you with the details), I thought this was a great page-turner and I can't wait until the next in the series comes out this fall!
In summary, this book follows the story of Kate Pierce-Keller, as she travels back in time to 1890's Chicago to save her timeline from being altered... and also to save her own life from being erased in the process.
I give the book itself 3.75 out of 5 stars. I give the cover art 10 out of 5 stars.