London is a plutocrat's paradise, with more resident billionaires than New York, Hong Kong or Moscow. Far from trickling down, their wealth is burning up the environment and swallowing up the city. But what do we really know about London's super-rich, and the lives they lead? To find out more, sociologist Caroline Knowles walks the streets of London from the City to suburban Surrey, via Kensington, Mayfair and elsewhere. Her walks reveal how the wealthy...