Margaret didn’t know whether to be pleased or pissed. Bob, she thought, could become pretty tiresome.

They were heading due west now along another six-lane highway running through a canyon of modern tower blocks. The sun was dipping lower in the late afternoon, dazzling through the dust and insects that caked the windscreen. Out of the haze, a sweeping flyover rose up from the road ahead. But at the last moment they bore right on to a smaller road thick with cyclists, and then right again into what looked like a building site.

“Here we are,” Bob said.

“We are?” Margaret looked with some horror.

They bumped across a pot-holed yard, raising a cloud of dust in their wake, and turned through a gate where a policeman stood endlessly to attention in the searing heat. He saluted as they passed. No one bothered to acknowledge him. Then suddenly they were on a private tree-lined road, a large all-weather games pitch behind a high fence on their left. They pulled up outside a tall white building with curled eaves and ornamental brown pillars.

Margaret got stiffly out of the car and was nearly knocked over by the heat. In the cool, cloistered air-conditioning of the BMW, she had forgotten how hot it was out there.

Bob pointed to a twenty-storey building beyond the administration block. “Staff live in there.”

“What?” Margaret was incredulous. “How many staff are there?”

“Oh, about a thousand.” He steered her through double doors and up dark marble steps in the cool interior.

“And how many students?”

“Around three thousand.”

Margaret gasped. A three-to-one student-teacher ratio was unheard of in the States.

“It’s kind of like the West Point for police in China. Down here.” And they set off down a long featureless corridor.

Margaret had had no idea the university was on such a small scale. She was seriously regretting now not having read her briefing material.

“Of course,” Bob went on, enjoying his possession of superior knowledge, “you’ll be interested in the pathology department and the forensics. That’s all down the far end of the playing fields. The Centre of Material Evidence Determination. They got some pretty sophisticated stuff down there, including a brand-new block with all the latest laboratory testing facilities—DNA, you name it. Stuff from all over China gets sent there. Christ, they even take ear-prints—you know, like fingerprints, only ears. But I got to admit, I can’t see many perps leaving their ear-prints at the scene of a crime, unless they’ve beaten somebody to death with their hearing aid.” He laughed at his own joke. But Margaret was distracted. His smile faded. “Not my field, of course.”

“What is your field?”