The classics and modernity clash in ‘Song of Achilles,’ a critically-acclaimed crossover of Greek myth, romance and historical fiction. ‘Achilles’ Trojan-horsed an Illiad prequel on your friendly neighborhood hosts, who expected an updated retelling of an ancient epic. Jon and Melissa interpret the fatal flaw in Madeline Miller’s debut novel, divining the difference between disliking her writing and disliking coming-of-age romances.