Revenge may be exacted a hundred times over in one sleepless night. The impulse, the dreaming intention, is human, normal, and we should forgive ourselves. But the raised hand, the actual violent enactment, is cursed. The maths says so. There’ll be no reversion to the status quo ante, no balm, no sweet relief, or none that lasts. Only a second crime. Before you embark on a journey of revenge, dig two graves, Confucius said. Revenge unstitches a civilisation. It’s a reversion to constant, visceral fear.

Ian McEwan