It's summer on Nantucket and Alison is finally engaged to the love of her life. Things would be perfect--if only she could make peace between her daughters. Felicity, wild at heart yet a loving mother to her own children, and Jane, the extremely organized and high-earning businesswoman, arrive on the island hoping to get through these next few weeks without ruining their mother's big day. But when Felicity's husband reveals a long-term affair and Jane falls for her soon-to-be step-brother, everyone gets way more drama than they bargained for.