The Unlikely Pilgrimage of Harold Fry, written by Rachel Joyce, is a poignant comedy drama book that follows the journey of Harold Fry, a recently retired man who sets out to deliver a letter to a dying friend. As Harold walks across England, he encounters a diverse cast of characters and reflects on his past, leading to personal revelations and unexpected connections. This book is a moving exploration of regret, redemption, and the search for meaning in life.