Gwen's Story was a great way to finish the series. You learn more and more about each character as you read each novel, and when you reach Gwen, you learn things about her that you never even realized in the previous novels. Gwen's story, I think, is the most tragic of the four in the set. It's definately a must read to end off the series. Also, Gwen's story goes into the 1930s, so you get to see how all of the other characters have developed over time (from Gwen's perspective, of course).