Li reached a junction fifty yards further on. He stopped, fighting for breath, and looked right and left. Nothing. Trees stirring lightly in the breeze. All that he could hear, apart from his own rasping breath, was the distant rumble of traffic on Dongzhimennei Street. He went right, walking past arched gateways to decaying siheyuan on both sides, peering in as he went. In the entrance to one, an old woman was sweeping up with a straw broom. He held out his Public Security wallet. “Police,” he said. “Did you see a man in a dark suit? He must have passed you.”

She shook her head. “I saw no one,” she said. “Except for some small boys about ten minutes ago.”

He turned immediately and started jogging back the way he had come, passing the junction where he had taken the right turn, and carrying on down to Dongzhimennei. The street was thick with traffic, a blur of bicycles in the cycle lane, the sidewalk crowded with pedestrians, a couple of street cleaners, some vegetable sellers. No one even gave him a second glance as he stood breathing hard, his face shining with sweat, looking one way, then the other. Johnny Ren was gone.

“Are you people blind!” he raged at his detectives when he got back. “You walk out of a meeting where this guy is the main topic of discussion. You all have a photograph of him in your folders. You come back in here and you don’t notice him walking out of my office?”

They all stood in stunned silence. The whole building was buzzing with rumour and speculation. Li’s first stop had been Chen’s office, where he had demanded armed guards on all entrances to the building, and that everyone coming in and out have their IDs checked. “I can’t believe this man’s audacity, Chief. We’re in the meeting room talking about how we’re going to catch him, and he walks into the building, cool as you like, and has all the time in the world to go through anything he wants to in my office.”

“Is there anything missing?” Chen asked.

“I don’t know. I’m going to have to go through everything on my desk.”

None of his detectives could say whether Ren had been carrying anything when he left Li’s office. “We just thought he was someone from downstairs in Administration,” Wu said. “No one paid him any attention.”

Li slammed the door of his office shut and stood seething. He looked around the room and felt sick. It was tainted somehow, dirty, violated. Johnny Ren was either supremely confident, or he was insane. Probably both. He clearly had complete contempt for the police.