Tours depart at 7.30, in time to reach the office by 9. En route, keen-eyed travellers search faces, gaits and speculate on destinations. There are no prizes but you will experience a cold satisfaction with every success. Most prized are the ones who hide behind a guise of bluff normality. It takes a real expert to catch the tiny glint of fear, the too-quick reflexive start at any human contact, the unwillingness to meet the gaze of their own reflections. But persevere and you too can add to your list. The longer your list the less likely you are to appear on someone else's.