A stranger proves to be the catalyst for a family who have lost their way, in this tale set on the Norfolk coast in the 1960s. After a life spent enjoying the cultural highlights with her late diplomat husband, Hannah (Jean Simmons) is content to while away her days in her remote Norfolk house overlooking the long sandy beaches and marshes. Filling her days with her garden and her poetry, she also enjoys the company of a young friend, Joe (Jamie Dornan), who helps her through a long term illness by supplying her with some cannabis. But when Hannah's son Robert (James Wilby) arrives along with teenage daughter Kate (Ophelia Lovibond) and son Sam (Toby Marlowe), relationships quickly become strained, as Robert's distrust of Joe's motives rises to the surface, reigniting old wounds. With the family intent on following their own agendas, a series of challenging events soon forces them to re-evaluate their lives and work through their differences.