How did one begin an investigation of a deputy procurator general without at least some proof? Who would authorise it? And who else might be involved? Not Chen, surely? But then, he had been so dismissive of the idea that Chao’s body had been deliberately destroyed, of the thought that Professor Xie might have been complicit in the incineration of blood and tissue samples. What was it they were so desperate to prevent him from discovering, and who stood to lose most from it?

Li knew he needed his uncle’s advice. Old Yifu would listen to everything he had to say without fear or favour. He would trust Li’s instincts but have a different perspective. His years of experience, of the police, of the justice system, his ability to calmly rationalise and sift through conflicting evidence, would be invaluable. More than ever before in his life, Li needed his uncle’s help now.

He drove past the Gate of Heavenly Peace, Mao’s portrait gazing down implacably upon the crowds in Tiananmen Square and his own mausoleum, a stern paternal figure remembered now with affection, his excesses and failures forgiven and forgotten. Past the gates of the Ministry of Public Security, and then right into the shady seclusion of Zhengyi Road. Immediately Li stood on the brakes, bringing his Jeep to a standstill. Near the foot of the road, outside the gates to the Ministry-provided police apartments where he lived with his uncle, were the blue and red flashing lights of several police vehicles and an ambulance. The road was blocked off, several uniformed officers milling on the sidewalk. Li felt a knot of nausea turn in his belly, and a cold sweat broke out across his forehead. He jammed his foot on the accelerator and sent the Jeep careering down the street to screech to a halt behind the ambulance. The uniformed officers turned in surprise as he leapt out of the car. “What’s happened?” he demanded.

“There’s been a murder,” said the senior officer.

Li looked up and saw all the lights on in his apartment, the shadows of figures moving around inside. He started running. “You can’t go up there.” The officer tried to stop him, but Li pulled free.

“I live there!”

There was no sign of the duty policeman as he ran to the front door of the apartment block. But inside, the ground-floor landing was swarming with uniformed officers. Li went up the stairs two at a time. Behind him he heard someone say, “That’s Li. Better radio up to the apartment.”