The Narrow Road to the Deep North by Richard Flanagan

August, 1943: Australian surgeon Dorrigo Evans is haunted by his affair with his uncle’s young wife two years earlier. His life, in a brutal Japanese POW camp on the Thai-Burma Death Railway, is a daily struggle to save the men under his command. Until he receives a letter that will change him forever.
 
A savagely beautiful novel about the many forms of good and evil, of truth and transcendence, as one man comes of age, prospers, only to discover all that he has lost.