Off season / Anne Rivers Siddons.

Enhanced descriptions from Syndetics:

Acclaimed novelist Anne Rivers Siddons's new novel is a stunning tale of love and loss. For as long as she can remember, they were Cam and Lilly--happily married, totally in love with each other, parents of a beautiful family, and partners in life. Then, after decades of marriage, it ended as every great love story does...in loss. After Cam's death, Lilly takes a lone road trip to her and Cam's favorite spot on the remote coast of Maine, the place where they fell in love over and over again, where their ghosts still dance. There, she looks hard to her past--to a first love that ended in tragedy; to falling in love with Cam; to a marriage filled with exuberance, sheer life, and safety-- to try to figure out her future. It is a journey begun with tender memories and culminating in a revelation that will make Lilly re-evaluate everything she thought was true about her husband and her marriage.