Reading Mathias Énard, one doesn’t sense any anxiety about the fate of the novel. Although some of Énard’s narrators play Tetris or log on to social media sites, they are generally bookish to the core and enamored of high culture, their own inner worlds, and the many connections that can be made between the two. In the work of the prolific French writer, one comes to expect certain things: historical details, geopolitical thinking, elevated, sometimes baroque prose, intoxicants, violence, voluptuous solitude, troubled personal affairs, and a manifold sensuality—a zest for music, facts, literary language, the things that, to use a word he is fond of, caress the mind. Énard’s leading men are students of their own shortcomings. They’re apt to say or do the wrong thing at the wrong time and feel the abyss open beneath them.…