One for Sorrow relates the story of the loss of 21-year-old Tom to cancer, and how his family lived through the aftermath. When Alan began writing the memoir, he believed it would be about his son's illness and death. He soon realized, however, that he was recording his own painful journey through the "valley of the shadow", as a father and as someone responsible for ministering to others in similar situations. His core beliefs were challenged and his perspective on life changed.