I think this is no more thna a thought-experiment for me these days, but in some ways it would be interesting to spend a couple of nights in London, riding on night-buses, back and forth, on different routes. To draw a flower-shape across the map of London, with Trafalgar Square at its heart, and petals defined by routes and walks around its edges.
What one would seek, through the haze of drinkers and screamers and quietly burbling nuts, would be the Night People themselves. these people, who don't exactly exist in a fixed state, are those that London is dreaming, as it sleeps with one eye open, watching a world larger than we can conceive. Such people are ghostly and frail, but more real than much of what we see or believe at 4am, and they are part of the London that has grown up in spite of and well as because of us. They are an aspect of us, and of what we create communally, crawling around the enchanted dung-heap.