Phoebe Stone arrives at a grand beachside hotel in Rhode Island wearing her best dress and least comfortable shoes. Immediately she is mistaken for one of the wedding people - but she's actually the only guest at the Cornwall Inn who isn't here for the big event.

When the bride discovers her elaborate destination wedding could be ruined by a divorced and depressed stranger, she is furious. Lila has spent months accounting for every detail and every possible disaster - except for,well, Phoebe... Soon, both women find their best-laid plans derailed and an unlikely confidante in one another.