Customarily, McEwan’s novels spring from a catastrophic incident in someone’s life, either a calamity that causes physical distress or a psychological trespass that causes emotional instability. For instance, in Enduring Love (1998), a man plunges to his death from a balloon, and in the aftermath, one witness continues to menace another witness. On Chesil Beach (2007) centers on an emotionally devastating wedding night. In his new novel, McEwan outdoes himself in terms of catastrophic occurrences. The protagonist, physicist Michael Beard, won a Nobel Prize several years ago and has been resting on his laurels ever since. A serial cheater, he is now married to his fifth wife, who leads a totally separate life, indicating her complete disdain for his wandering eye. His lack of effort in...