As she walked down the train carriage, Annie composed an imaginary autobiography, selecting and categorising what she considered to be key facts about herself for an imagined posterity. When she was eight, she had eaten an ice-cream sandwich so cold it had given her a migraine. In her first year of university, she had lost a pair of socks when they had fallen out of her fifth-floor window. She only ate blackcurrant yoghurts when she felt she had earned them. Her bellybutton was slightly deeper than she would ideally like, plunging from the gentle curve of her stomach down into a tiny pit of wrinkled skin and fluff. It had been knotted by the midwife, whose name she did not know, in such a way as to leave a miniature knuckle of umbilical cord down at the base of the pit, like a grey-pink boulder plugging the hole. The colour of the fluff that formed in it seemed to be completely independent of the colour of the clothes she wore, emerging as small bundles of mysterious greyish lint. Sometimes, while she sat on her bed gazing at it, she imagined her navel was a separate creature in its own right, quietly observing the world from belly-height – the thought both thrilled and disgusted her.