Midnight on St Mary Street in Cardiff and everything is exactly as expected. Half a dozen young women slump in a gutter, men urinate outside a health-food shop and, as hordes stagger between nightclubs, someone lifts up a blow-up doll with a sex toy protruding out of it. The street smells of urine and lager, police struggle to break up a fight outside the Walkabout bar and a paramedic bundles a comatose girl on to a wheelchair. But it's a quiet night for 20-year-old Naomi Jenkins. She has 'only' drunk three shots of peach schnapps, cider and three shots of...