It was one thing for me to have encountered a fracture in the normal progression of time, but the idea that he had played a part in my day and that he had had conversations and done things he could not remember obviously gave him the same feelings of faintness and unease which I had had when I saw that slice of bread drifting floorward. That strange moment when the ground under one’s feet falls away and all at once it feels as though all predictability can be suspended, as though an existential red alert has suddenly been triggered, a quiet state of panic which prompts neither flight nor cries for help, and does not call for police, fire brigade or ambulance. It is as if this emergency response mechanism is there on standby at the back of the mind, like an undertone, not normally audible, but kicking in the moment one is confronted with the unpredictability of life, the knowledge that everything can change in an instant, that something which cannot happen and which we absolutely do not expect, is nonetheless a possibility. That time stands still. That gravity is suspended. That the logic of the world and the laws of nature break down. That we are forced to acknowledge that our expectations about the constancy of the world are on shaky ground. There are no guarantees and behind all that we ordinarily regard as certain lie improbable exceptions, sudden cracks and inconceivable breaches of the usual laws.