A phantasm of a phantasm. Deep in the cat's psyche is a knowledge of how to hunt, but it never does. It lives in London. It's never let out to stalk and catch a robin, a thrush, a linnet. In its little animal brain the cat dreams of hunting, but its life is packet food and saucers of milk, and the affections of everyone in the pub where it wanders unobstructed, hopping onto a stool, prowling under a table, accepting the amused stroking of customers.

Sarah did something I have never seen done before. She has found that the cat plays with light. Pure black he is, Harry, very elegant, not haughty as a cat can be, but curious and adventurous. She loves him. On the nights she works she rushes around, but always she has time to play with Harry, to let him through, to stop and crouch and treat him as an equal. Sarah likes the play too. She is intelligent; she sees possibilities; she experiments.

So she takes a spoon, and in the dull reflection of the yellow overhead lights she flicks a little white spot of light across the floor. Harry sees it: he stalks it, he pounces on it, he drags his paw tentatively over its ecliptic track to watch how it moves. Sarah moves it for him in a way he can follow. She is patient, she is loving.

To her it is a kind of game, bringing things into his sight and taking them gently away; to him it is what he too does for sport, the harmless stalking, the feline pastimes that you can do in the comfort of warmth and food. The race memories are there, the genes have given him an understand of what his kind did when they had to, but there is something childlike and consensual in his wondering play.

If you drag a skein of wool before a cat it tackles it like a mouse, but a mouse in play: where its livelihood does not depend on ending the strange questing game. An echo of a former life. Sarah drags a transient faint beam around Harry, and he responds: echo of echo.