The Summer Guests by Tess Gerritsen

It's Susan's and her teenager Zoe's first visit to Purity, Maine after Susan married Ethan Conover. Soon after their arrival, Zoe disappears. Acting police chief Jo Thibodeau wonders what could have happened to her. The Martini Club (four retired CIA agents--Maggie, Declan, Ben, and Ingrid) decide to get involved, much to Jo's dismay. Could Zoe's disappearance be connected to murders over fifty years ago one July day? The Summer Guests continues the adventures of the Martini Club. I loved the first book in the series and had high hopes for this one, but it's a miss for me. The book focused on too many characters instead of developing a few of them really well. In addition, the mystery itself wasn't that interesting. It will be published in March.