What the description of the book does not mention is the ghost and the ghost is a very important character in Dream Lake. Lisa Kleypas uses the ghost to tell the backstory in the first chapter of the book. Although this is Alex and Zoe's story the ghost plays an interesting part in the story.
Even though Dream Lake runs in time parallel to Rainshadow Road you do not see much of the other two brothers in this book. Alex and Zoe were introduced in previous books and both have issues. On the surface they are not a good match. Zoe knows that Alex is nothing but trouble and Alex sees Zoe as someone who needs commitment, something he feels he is not capable of giving It's is the ghost that keep telling Alex he is missing a bet if he does not pursue Zoe.
Dream Lake does have an interesting journey to the HEA. In addition to all of the other problems that Alex and Zoe face Lisa Kleypas weaves the problems a family faces when someone is diagnosed with dementia. It is used as an effective plot device but offers a lot of information about the progression and how it affects the lives of friends and family. I found that element very well done.
I think Dream Lake does a very good job of continuing the Friday Harbor series. The addition of the ghost makes this a paranormal romance. There is a set up in Dream Lake for book four to have a paranormal romance element also. That adds a little more spice to the series.