I WRITE TONIOGHT in a hotel room supplied by two congenial governments, having sent away the evening’s inevitable prostitute. My window looks across an ocean of stray light. Chaotic currents updrift into the satellite maps I know of Beijing, where the light hovers above the landmass in meaningful, portentous colours. There are no stars.

Officially, I am part of a disembodied team of ‘foreign experts’ here to advise the Central Committee on preparations for the Olympics: my fields are noise and light pollution. My true reason for returning to China was to find a girl I left here in her first year of study at Beijing Foreign Language University, with whom I lost contact, and with whom I shared the most extraordinary few moments I shall ever live. Hao Xue’s name means plenty of snow. It was given her by the weather on the day of her birth. She might be a diplomat or translator by now, and I worried that she might be far from Beijing, the city she had introduced me to three years ago.