"With rumors of infidelity straining Greg and Tess MacAvoy's marriage, the couple head out on their sailboat on early-summer day to celebrate their wedding anniversary, hoping the roughest waters are behind them. But in a mysterious accident off Nantucket, they drown, leaving behind two small children as well as three couples who have long been their closest friends. The tragedy brings to the surface long-simmering conflicts and emotions, and the...