And so he told her. About the CD on pause, the empty bottle on the table on the balcony, the cigarette ends in the ashtray, the lamp missing from the light over the front door. He painted for her his picture of what he believed happened that night: Chao Heng forced back to his apartment at gunpoint then knocked on the head and sedated; the patch of blood left on the carpet which, he felt sure, would be Chao’s, and which spectral analysis would show to be around twelve to fourteen hours old; the killer carrying the prostrate body of the agricultural adviser down the staircase, locking the stair gate behind them; the drive to the park, the long wait among the trees, and then the immolation and the killer’s escape to anonymity seconds before the blazing body was found.

She sat listening in silence. “I hadn’t thought through the planning that must have gone into it. Not in that kind of detail. In my job you are so preoccupied with the details of death that you don’t think much about motivation, or premeditation.” She fell silent again, thinking about it some more. “It’s extraordinary, when you examine it. Why would somebody go to such lengths? I mean, it wasn’t even as though it was a particularly convincing suicide.” She turned it over again in her mind. “Are you sure these three killings are connected?”

“No, I am not sure.”

“I mean, they were all professionally executed, but the other two were simple, uncomplicated, almost casual. Chao Heng’s killing was . . . bizarre and ritualistic and, if you are right in your assumptions, minutely plotted and planned.” She turned to look at him. “You’ve eliminated a drugs connection, right?” He nodded. “So all that’s left to connect them are the cigarette ends.” He nodded again. “And, God knows, that’s pretty damned weird.” She frowned. “Something not right. Something really not right.” And for a fleeting moment she understood his obsession, was touched by a feeling both ephemeral and elusive, which he might have called instinct. A feeling that left her uneasy and uncertain, but intrigued. “Tell me about Chao Heng.”

As he drove along Chang’an Avenue, he recapped for her the details from the file he had been given on Chao Heng. “Retired due to ill health?” she mused. “What was wrong with him?”

“I’ve no idea. His bathroom cabinet was full of medicines.” He turned into Zhengyi Road and parked in the street outside the police apartments. “I’ll be five minutes,” he said.