underwear on show. She has lost one of  her shoes. The ambulance crew try to rouse her, but she is barely able to speak. She is helped into the ambulance, legs buckling as she tries to walk. Once inside, she rouses herself sufficiently to abuse the crew. Toni Agnew, 42, a paramedic with 21 years' experience, calms her down as she ascertains her condition. 'If people are drunk they can't  tell you what's wrong, so we have to check everything,' she says. 'We check glucose levels as diabetes may be the reason for their passing out.' Blood pressure and pulse rate  are taken as these can indicate drug use. Pupil size is checked in case of  head injury, and they are given an AVPU score (Alert, Verbal, Pain and Unresponsive). Helen may be almost catatonic, but her aggression is terrifying. 'What are you looking at?' she demands of me. I shrink back in  my seat, concealing my notepad as best I can. She is dropped off at the  nearest A&E. 10.26pm There is a pool of viscous red liquid on the white floor of the McDonald's restaurant on London's Shaftesbury Avenue. Our first, horrifying thought is that it must be blood. There are scarlet stains on the cream cardigan of the pretty girl slumped unconscious in a chair. When she is roused she smiles  beatifically and allows herself to be helped, unharmed but drunk, into the ambulance. The stench of vomit and red wine follows her. Drunk: Camellia was on