In the glaring white heat of the plains, it&rsquos easy to hallucinate. I see the ghats of Varanasi long before we reach them Varanasi (or Banaras) always takes me by surprise, emerging in ramshackle, dusty bits and pieces from a grey winter or the blank ferocious heat of summer, one of the oldest living cities in the world stumbling out at you absently, ambushing unwary tourists and jaded pilgrims with equal impartiality.