Sometimes a book can be difficult to read, perhaps difficult because of the quantity of information presented, perhaps difficult because it makes us uncomfortable, or sad, or because it shines a bright light on ugly human flaws which we’d rather not think about. But that book might need to be read over and over again to really experience it fully, discomfort notwithstanding. Naomi Ragen’s fourteenth novel, “The Enemy Beside Me,” is just such a novel because of the intense spotlight she shines on a country that to this day refuses to admit its part in the massacre of its Jewish population, and because of the amount of information she presents, factual first person accounts, about those horrific events.