The social and class divisions in early 20th century England through the intersection of three families - the wealthy Wilcoxes, the gentle and idealistic Schlegels and the lower-middle class Basts.

Harold Fry is an unremarkable man who has made mistakes with all the important things: being a husband, a father and a friend. And now, well into his 60s, he is content to fade quietly into the background of life. Until, one day – Harold learns his old friend Queenie is dying. Harold leaves home, walking to his post office to send her a letter. And out of the blue, Harold decides to keep walking, all the way to her hospice, 450 miles away.

During a long, hot summer on the Thamesmead Estate in Southeast London, three teenagers edge towards adulthood.