Chongqing, now China's most densely populated city, is undergoing drastic upheaval. Once the centre of Chairman Mao's armaments industry, its factories are now crumbling and its socialist institutions are in decline. A new faith in market forces has led to a huge disparity in the distribution of wealth and a surge in crime - situation far removed from the egalitarian society envisaged by Mao. The Liaos, once Red Army guards and now affluent restaurateurs, represent a new class of self-made capitalists. But single mother He Xiaoxia has lost her livelihood and, along with millions of other jobless Chinese, faces a bleak future. Isobel Hilton meets the rich and poor of Chongqing in a report exposing the human face of China's "economic miracle".