Another batch of statements was carried in and distributed on the piles beneath the window. Through the open door he saw that the detectives’ room was still a hive of activity. He lifted the file on Chao and flipped it open. There was precious little detail here. Born 1948, in the town of Nanchang in Jiangxi province, the year before the founding of the People’s Republic of China. His father was a professor of English and his mother a Party cadre. He came to Beijing in 1966, the year Li was born, and enrolled at Beijing Agricultural University just as the Cultural Revolution was sweeping the country. Two years into a degree course in agronomy and crop sciences he was denounced by fellow students turned Red Guards and forced to drop out. The phrase denounced by Red Guards conjured for Li images of repeated beatings, hours of enforced self-criticism, endless essays confessing to reactionary weaknesses and imperial tendencies. Often it was simply an opportunity for adolescents, freed from the constraints and disciplines of an organised and civilised society, to explore the dark and cruel side of their human nature. Bullies and brutes given the freedom to express themselves in torture and murder without fear of retribution. They were, after all, only cleansing their country of its class enemies, those upholders of the Four Olds. Children were freed to taunt and torment their teachers, forcing them to wear dunce caps and grovel before them in class. Li had witnessed it first hand in his own primary school. Fortunately, by the time he reached middle school, the madness had just about run its course. He imagined that Chao’s fellow students had probably picked on him because he was soft, perhaps overtly homosexual, perhaps simply still confused about his sexuality. He was sent to the countryside for re-education.

Here there was a gap in the record of nearly a year. There was no indication of where he had been sent. Either through extraordinary good fortune, or through some influence that his mother had been able to bring to bear, he suddenly turned up in the United States enrolled as a student at the University of Wisconsin. Graduating in 1972 in microbial genetics, he stayed on a further year to complete a postgraduate doctorate in biotechnology. And then he won a research fellowship to the Boyce Thompson Institute at Cornell University, where he remained until 1980, when he returned to China to teach at the very university he had been forced to abandon twelve years earlier.

He had married very quickly then, but was divorced again within three years, during which time he had managed to father a daughter. Li wondered why he had felt the need to marry. Clearly it was always going to be a relationship doomed to sexual failure. Was there really a need to create a veneer of heterosexual respectability? Might he not just have been discreet in his lifestyle?