As if driven by an inescapable force, Isabel (Michelle Williams) has devoted her life to running an orphanage in a Calcutta slum. With funds running dry, a potential donor, who requires she travel from India to New York, to deliver a presentation in-person, contacts Isabel. At first balking at the demand of an uncommitted philanthropist, she relents, and travels to a city she deliberately hasn't returned to in over two decades.

Once in New York, Isabel lands uncomfortably in the sites of the orphanage's possible benefactor, Theresa Young (Julianne Moore), a multi-millionaire media mogul. From the glittering skyscraper where she runs her successful business, to the glorious Oyster Bay estate, where she lives happily with her artist husband, Oscar Carlson (Billy Crudup), 21-year-old daughter, Grace (Abby Quinn), and eight-year-old twins, Theo and Otto, Theresa's life couldn't appear to be more perfect. But appearances are only skin deep, and Isabel and Theresa have more in common than meets the eye.

While Isabel thinks she'll soon be returning to her beloved orphanage, Theresa has other plans. She insists Isabel attend Grace's wedding at the family's estate. The joyful event becomes a catalyst for a revelation that upends the lives of both women, and the people who love them most.