The Unlikely Pilgrimage of Harold Fry by Rachel Joyce follows the adventures of an unlikely pilgrim on an unlikely pilgrimage. Harold is not a person of faith but when he gets an unexpected letter from someone who he has not seen for twenty years, but who did him a massive favour at that point, he is so moved by the news that she is dying that he decides that the letter he has written is not enough - and so he sets out to walk to see her, even though he is in south Devon and she is in Berwick-on-Tweed.
The book is the story of the "pilgrimage". As you might expect, Harold has many interesting encounters and reflections.
Essentially, though, it is a story of someone doing something on the spur of the moment, which might seem crazy, but which he simply has to do.
Are there things that we are not doing that it ought to be that we have to do? Where should we be going on pilgrimage?