This is what they did. On the day of the operation a nurse arrived wielding a big black felt-tip pen. She daubed a large arrow directly onto the flesh at the top of my thigh. The arrow was pointing downwards, towards the knee that required some urgent attention. A little later, a doctor came along with a Permanent Magic Marker (these have a slightly copper tinge to the black ink) and drew over the arrow, several times, reinforcing the original mark. This meant that the emergency helicopter had not arrived during the afternoon, and the scheduled op (last of the day) could go ahead. An anaesthetist knocks me out in a prep room decorated with drawings of bunnies and puppies. A surgeon