I n Yann Martel’s fifth novel, a Canadian classicist, Harlow Donne, has been offered a year’s fellowship at Oxford University. His wife, Gail, has a full-time managerial job, and they have a seven-year-old daughter, Helen. Who will pour out her breakfast cereal and pick her up from school while Harlow is away? He and Gail quarrel. He leaves for England, and as she sees him off Gail whispers in his ear: “Don’t come back.” So far, so everyday: but once Harlow gets to Oxford, the narrative shifts its form and becomes odder and more interesting. His prescribed task is to help sift through and translate a hoard of ancient papyri from Oxyrhynchus, in upper Egypt. It’s tedious work. Soon, though, Harlow is piecing together from words or half-words on wisps of desiccated reeds what he believes to be a long-lost epic poem. It relates the story of the Trojan war, but not, as Homer tells it, from the viewpoint of princely warriors and gods. The protagonist is a common soldier, a “son of nobody” named Psoas.…