The force of the idea was such that I drew the car to the side of the road and stopped and, for some reason, laughed. It was a loud laugh, unsteady, and sounded, even to my own ears, slightly maniacal. Thinking back now, I realise it was less a laugh than the birth-cry of my dark and twin brother Benjamin Black.

John Banville on the birth of his dark twin, Benjamin Black (2011)