When I was little, I lived in the big tank, an enormous empty space with hundreds of other fish. The girls told me how to attract the customers. ‘Make yourself look pretty,’ they said. ‘You want to be chosen.’ I groomed my scales and fluffed up my tail. I perfected the art of flitting this way and that to show how streamlined I was. There was a particular place about halfway along the tank, where a spotlight hit it. That’s where I turned. I folded gracefully over myself, let my tail fan out and trail behind me, paused for a moment, gave a quick, shimmering pulse and darted away. I practised that move again and again. It worked. I was hired by a modelling agency. It was the happiest day of my life.