Li read it over a couple of times. He had no idea what any of it meant, or why he was going to be shown these things. Pan looked up from her computer screen, positioned so that she would be looking at Li in profile while he was looking at his monitor. ‘All set?’ she asked.
‘I guess,’ Li said. ‘Left-hand button for everything on this list, right-hand button for everything else.’
‘You got it.’ And then it was as if she flicked off a charm switch and became another person. Cool, focused, impersonal. ‘At the risk of making you conscious of it, I’m going to ask you to try to blink as seldom as possible when I am showing the images. Alright?’
‘Alright.’
‘Focus on the screen. The images will appear for only three-tenths of a second, so please concentrate. There will be three seconds between each image, but try to respond with the mouse button immediately. You will see a total of fifty-four images. It will take approximately three minutes. We’ll have a rest, and then we’ll start again.’
Li found himself inexplicably tense in anticipation of it and had to make himself consciously relax his grip on the mouse. He flicked a glance at the list, afraid he might have forgotten something on it.
‘Eyes on the screen please.’
His eyes jumped back to the screen and the sequence began. It was all so fast it was hard for him to think consciously about any of the images he saw. The red car with the missing fender, the bloody shirt on the drive at the crime scene, a Swiss army knife, an apartment block that meant nothing to him. It seemed like a long three minutes. He saw one of the pictures of the crime scene that Pan’s graduate had shown them, and the close-up of the man with the back of his head missing. He saw a grey Nissan car that he did not recognise, the statue of Mao from his home town, the murder weapon he had handled only half an hour earlier. There were images of an axe, a licence plate he did not know, a dress with blood on it, the bizarrely familiar pink and white of the police apartment block where he lived in Zhengyi Road.
And then it was over, and Pan was smiling at him, the charm switch flicked back to the on position. ‘Just relax, Li Yan,’ she said, suddenly informal again, familiar. He allowed himself to blink, and sat back in his chair. The concentration the test had required of him had left him feeling fatigued. And, as if reading his mind, she said, ‘It’s tiring, isn’t it?’
He nodded. ‘Are you going to tell me now how it works?’
‘Not yet. We’re not finished. I’m going to show you the same pictures again, although not in the same order. The computer will randomise them. But I need you to treat them in exactly the same way. Left-hand button for the targets, right-hand for everything else. Okay, you ready?’
In fact, they ran through the images another twice before she finally turned on her sweetest smile and told him it was all over. She came back around the desk and removed his headset. ‘How long will it take you to figure out whether I was one of those briefed on the crime or not?’ he asked.
‘I know already.’ This quite matter-of-factly.
He was intrigued. ‘So, tell me.’
Her smile turned secretive. ‘Not yet. I’m saving that for the finale.’ She lifted his list of targets and slipped it back into his folder. ‘But I will tell you exactly what it is I just put you through. And why.’ She adopted her sitting position on the edge of the desk again, her legs stretched out in front of her, arms folded. ‘It’s just a demonstration program,’ she said, ‘but basically it consists of me showing you fifty-four images. Nine of these are what we call probes. That is to say, they relate specifically to the crime that three of you were briefed on. Images that you would recognise instantly if you were one of those three. Another nine of the fifty-four were the targets that I gave you a list of. Each target corresponds to one of the probes. For example, your apartment block would correspond to the private dwelling house where the murder took place. You recognise your apartment block, and if you are one of those briefed, you recognise the murder house. Your brain emits the same recognition signal, the same MERMER.’
‘What about the other thirty-six?’
‘Irrelevants. That’s what we call them, because that’s what they are. Irrelevant. Although again, a number of them will correspond to the probes. So that you see your apartment block, the murder house, and some other apartment block that means nothing to you.’
The logic of it began to drop into place for Li. ‘Okay, I get it,’ he said. ‘You use my apartment block as the benchmark. The thing you know is familiar to me. If you get the same reading from the murder house, you know I’ve been briefed. But if the murder house and the irrelevant apartment block give the same reading, which is different from my apartment, you know I haven’t.’
She half-nodded, half-shrugged. ‘I guess that comes somewhere close to it. I would probably have said that the determination of guilt or innocence consists of comparing the probe responses to the target responses, which contain a MERMER, and to the irrelevant responses, which do not.’
Li let the implications tumble around in his mind. ‘That’s extraordinary,’ he said finally. ‘If it works.’
‘Oh, it works.’
‘You would know beyond doubt that a guilty suspect had knowledge of a crime scene that only the culprit could possess. And you could instantly rule out an innocent suspect if you could demonstrate that they had no recognition of specific elements of the crime or the crime scene.’
‘Which has been done,’ Pan said. ‘In the States. Where Doctor Farwell demonstrated to an appeal court that a man who had served twenty-two years of a prison sentence for murder had no details of the crime scene stored in his brain, while the details of his alibi were. And that evidence was ruled admissible by the judge.’ She laughed to herself. ‘Unlike poor old Bill Hart’s dinosaur technology. I can’t think of a single court anywhere that accepts the polygraph test as evidence.’
‘You don’t think much of the polygraph, then?’
‘I don’t. In a conventional polygraph test, emotion-driven physiological responses to relevant questions about the situation under investigation are compared to responses to control questions which are invasive and personal and not relevant to the issue at hand. Their only purpose is to emotionally and psychologically disturb the subject. So even if the subject is innocent, and truthful, he is subjected to a highly invasive and stressful ordeal. I don’t think you could say that about the MERMER test, do you?’
Li had to agree. ‘Not at all.’
‘The trouble with the polygraph, Section Chief, is that it’s not science. It’s artful and disturbing psychological manipulation.’
Li blew air through pursed lips. ‘You and Margaret would get on like a house on fire.’
Pan inclined her head. ‘Margaret …’ she repeated the name. ‘Campbell?’ Li nodded. ‘She’s quite a character, I hear. I’d like to meet her.’
‘If you can make it tonight you will.’ He stood up, his height restoring the mantle of dominance she had taken from him and worn herself during the test. But she didn’t seem to mind. The warmth in her eyes as they met his was unmistakable, and the twinkle in them suggested she was flirting.
‘I will do my very best to be there,’ she said. She stretched out a hand to shake his, and held it as she spoke. ‘It’s been a real pleasure, Section Chief.’
III
Margaret watched as a mother lifted her child into the shiny brass seat of the rickshaw. The little girl was perhaps three years old, drowned by a quilted red jacket, a sparkling red band keeping her long, black hair out of her face. Thousands of backsides had polished the seat to a brilliant shining gold. The rest of the life-sized statue was tarnished and dull, including the rickshaw man with his shaved pate and his long pigtail. A camera flashed in the afternoon sunshine. A few yards away a middle-aged man swept his hair self-consciously to one side as he posed for his wife’s camera with a couple of brass musicians. A man with a suit and an umbrella stood beside a brass barber shaving the head of an eternally acquiescent client. A half-empty open-sided blue tourist bus crawled past, the tour guide barking the history of Wangfujing Street through a speaker system that filled the air. The name Wangfujing derives from a fifteenth century well … No one was listening.