Chen had a face like sour milk. Li said, “Actually, Detective, I think you would probably benefit more from a couple of years’ experience on traffic duty in Tiananmen Square.” Which allowed the others to release their pent-up laughter. “You and I can take shift about.” More laughter. Li glanced at Chen, on whose face had appeared the faintest glimmer of a smile. “And in answer to your question, Wu, Dr. Campbell will no longer be assisting us with the inquiry.” He closed his folder. “That’s all just now, unless there’s anything else?” There wasn’t. “Okay, let’s go catch Johnny Ren.”

As chairs scraped on the floor, and cigarettes were stubbed out in ashtrays, Li said, “Just one more thing. Keep the paperwork coming into my office down to a bare minimum, guys. Essential stuff only, please. I’ve got enough already in there to keep me fully occupied for the next five years.”

The detectives drifted out. Chen wandered up the table to Li and touched his shoulder lightly. “Keep me in touch with developments.”

Li sat for a moment after they had all gone, and found himself filled with a strange, aching melancholy. He picked up his folder and forced himself to stand up. He seemed to have lost all energy. Perhaps, he told himself, it was simply his hangover. He walked slowly back down the corridor. Although he had made light of Wu’s reference to Margaret, it had forced him to face the truth—that without her involvement in the investigation he had no real reason for seeing her. At least, not professionally. And the demands of the job were such that he wasn’t likely to have much free time in the foreseeable future. In less than five weeks she would be gone and he would be unlikely ever to see her again. So it would be pointless trying to pursue any kind of relationship in the few hours they might have together between now and then. And without the case to discuss, what would they talk about? It wasn’t as if they had much in common. In fact, it was insane for him ever to have considered that there might be something between them that could form the basis of a relationship. It was as well that an end had been put to it now. But however convincingly he told himself this, he remained resolutely unconvinced. He was deeply depressed at the thought that she might already have slipped out of his life for ever.